This is a list of states in the Holy Roman Empire beginning with the letter M:
| Name | Type | Imperial circle | Imperial diet | History |
|---|---|---|---|---|
 Magdeburg | Archbishopric | Low Sax | see Duchy | 968: Formed 1180: Imperial immediacy 1680: Secularised as Duchy for Brandenburg |
 Magdeburg | Burgraviate | n/a | n/a | c. 1000: Enfieffed to Walbeck 1080: Enfeoffed to Herman of Spanheim 1118: To Groitzsch 1136: Enfeoffed to Querfurt 1178: To Querfurt-Magdeburg 1269: To Saxe-Wittenberg |
| Magdeburg | Duchy | Low Sax | PR | 1680: Archbishopric of Magdeburg secularised as Duchy for Brandenburg 1807: Dissolved; west to Westphalia, east to Prussia |
| Maidburg-Hardegg | Burgraviate | n/a | n/a | 1278: Younger branch of Querfurt-Magdeburg assumed the name Maidburg-Hardegg after inheriting Hardegg 1481: To Austria 1484: Extinct |
 Mainau | Commandry of the Teutonic Order | Swab | n/a | 724: To Reichenau Abbey 1271: To the Teutonic Order 1730: Acquired Dettingen, Dingelsdorf and Litzelstetten 1783: Acquired Allmannsdorf 1806: To Baden |
 Mainz | Archbishopric 1356: HRE Prince-Elector | El Rhin | EL | 4th Century: Formed 780: Archbishopric 1356: HRE Prince-Elector 1803: To the Archbishopric of Regensburg |
 Mainz | Imperial City | n/a | n/a | 1244: Free Imperial City 1462: To the Archbishopric of Mainz |
 Malberg | Lordship | n/a | n/a | 1273: Acquired by Reifferscheid; to the Elder Line 1302: To Luxembourg |
 Manderscheid | Lordship 1457: County | n/a | n/a | 1133: First mentioned 1445: Acquired Schleiden 1457: HRE Count 1469: Acquired Blankenheim 1488: Partitioned into Manderscheid-Schleiden, Manderscheid-Blankenheim-Gerolstein and Manderscheid-Kail |
| Manderscheid-Blankenheim | County | Low Rhen | WE | 1530: Partitioned from Manderscheid-Blankenheim-Gerolstein 1780: Extinct in male line; to Sternberg-Manderscheid by marriage |
| Manderscheid-Blankenheim-Gerolstein | County | Low Rhen | WE | 1488: Partitioned from Manderscheid 1530: Partitioned into Manderscheid-Gerolstein and Manderscheid-Blankenheim |
| Manderscheid-Gerolstein | County | Low Rhen | WE | 1530: Partitioned from Manderscheid-Blankenheim-Gerolstein 1697: Extinct; to Manderscheid-Blankenheim |
| Manderscheid-Kail | County | Low Rhen | WE | 1488: Partitioned from Manderscheid 1742: Extinct; to Manderscheid-Blankenheim |
| Manderscheid-Schleiden | County | Low Rhen | WE | 1488: Partitioned from Manderscheid 1545: Acquired Virneburg 1560: Partitioned into Manderscheid-Schleiden-Kerpen and Manderscheid-Schleiden-Virneburg |
| Manderscheid-Schleiden-Kerpen | County | Low Rhen | WE | 1560: Partitioned from Manderscheid-Schleiden 1583: Under Imperial ban 1593: Extinct; divided between Manderscheid-Kail and Mark-Schleiden in succession dispute |
| Manderscheid-Schleiden-Virneburg | County | Low Rhen | WE | 1560: Partitioned from Manderscheid-Schleiden 1590: Extinct in male line; to Manderscheid-Gerolstein by marriage 1639: To Löwenstein-Wertheim-Virneburg by marriage |
 Mansfeld | County | n/a | n/a | c. 1050: First mentioned as a title of the gau counts in Hassegau 1112: Count of Mansfeld primary title c. 1215: Partitioned into itself and Friedeberg 1229: Extinct; to Querfurt-Mansfeld 1246: Querfurt-Mansfeld assumed the name Mansfeld 1266: Partitioned into itself and Schraplau 1273: Partitioned into Mansfeld Elder Line and Mansfeld Younger Line |
| Mansfeld-Arnstein | County | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1580: Mediatised; 3/5 to Saxony, 2/5 to Magdeburg 1615: Extinct; divided between Mansfeld-Artern, Mansfeld-Bornstedt, Mansfeld-Eisleben and Mansfeld-Friedeburg |
| Mansfeld-Artern | County | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1580: Mediatised; 3/5 to Saxony, 2/5 to Magdeburg 1631: Extinct; divided between Mansfeld-Bornstedt and Mansfeld-Eisleben |
| Mansfeld-Bornstedt HRE Prince and Prince of Fondi, Count and Lord of Mansfeld, Noble Lord of Heldrungen, Seeburg and Schraplau, Lord of the Lordship of Dobrzisch, Neuhaus and Arnstein | County | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1580: Mediatised; 3/5 to Saxony, 2/5 to Magdeburg 1780: Extinct; Saxon portion to Saxony, Magdeburgian portion to Magdeburg. Mansfeld property in the Habsburg domain to Austria 1789: Austrian fiefs to Colloredo-Mansfeld |
| Mansfeld-Eisleben | County | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1580: Mediatised; 3/5 to Saxony, 2/5 to Magdeburg 1710: Extinct; to Mansfeld-Bornstedt |
| Mansfeld Elder Line | County | n/a | n/a | 1273: Partitioned from Mansfeld 1313: Extinct; to Mansfeld Younger Line |
| Mansfeld-Friedeburg | County 1594: Principality | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1580: Mediatised; 3/5 to Saxony, 2/5 to Magdeburg 1594: HRE Prince 1626: Extinct; divided between Mansfeld-Artern, Mansfeld-Bornstedt and Mansfeld-Eisleben |
| Mansfeld-Heldrungen | County | Upp Sax | WT | 1563: Partitioned from Mansfeld-Vorderort 1572: Extinct; divided between Mansfeld-Arnstein, Mansfeld-Artern, Mansfeld-Bornstedt, Mansfeld-Eisleben and Mansfeld-Friedeburg |
| Mansfeld-Hinterort | County | Upp Sax | WT | 1501: Partitioned from Mansfeld Line 1 1547: Under Imperial Ban 1552: Imperial Ban lifted 1560: Partitioned into Mansfeld-Hinterort Elder Line, Mansfeld-Hinterort Intermediate Line and Mansfeld-Hinterort Younger Line |
| Mansfeld-Hinterort Elder Line | County | Upp Sax | WT | 1560: Partitioned from Mansfeld-Hinterort 1666: Extinct; divided between Mansfeld-Bornstedt and Mansfeld-Eisleben |
| Mansfeld-Hinterort Intermediate Line | County | Upp Sax | WT | 1560: Partitioned from Mansfeld-Hinterort 1628: Extinct; to Mansfeld-Hinterort Elder Line |
| Mansfeld-Hinterort Younger Line | County | Upp Sax | WT | 1560: Partitioned from Mansfeld-Hinterort 1594: Extinct; divided between Mansfeld-Hinterort Elder Line and Mansfeld-Hinterort Intermediate Line |
| Mansfeld Line 1 | County | n/a | n/a | 1420: Partitioned from Mansfeld Younger Line 1442: Acquired half of Friedeburg, and Salzmünde 1482: Acquired Heldrungen 1492: Extinct; to Mansfeld Line 2 |
| Mansfeld Line 2 | County | n/a | n/a | 1420: Partitioned from Mansfeld Younger Line 1449/52: Acquired Artern 1501: Partitioned into Mansfeld-Vorderort, Mansfeld-Mittelort and Mansfeld-Hinterort |
| Mansfeld Line 3 | County | n/a | n/a | 1420: Partitioned from Mansfeld Younger Line 1442: Acquired half of Friedeburg 1499: Extinct; to Mansfeld Line 2 |
| Mansfeld-Mittelort (Mansfeld-Schraplau) | County | Upp Sax | WT | 1501: Partitioned from Mansfeld Line 1 1602: Extinct; to the lines of Mansfeld-Hinterort |
| Mansfeld-Vorderort | County | Upp Sax | WT | 1501: Partitioned from Mansfeld Line 1 1563: Partitioned into Mansfeld-Bornstedt, Mansfeld-Eisleben, Mansfeld-Friedeburg, Mansfeld-Arnstein, Mansfeld-Artern and Mansfeld-Heldrungen 1580: Mansfeld-Vorderort mediatised; 3/5 to Saxony, 2/5 to Magdeburg |
| Mansfeld Younger Line | County | n/a | n/a | 1273: Partitioned from Mansfeld 1420: Partitioned into Mansfeld Line 1, Mansfeld Line 2 and Mansfeld Line 3 |
 Marchtal | Abbacy | Swab | SP | bef. 776: Formed 1500: Imperial immediacy 1803: To Thurn and Taxis 1806: To Württemberg |
 Mark (Marck) | 1198: County | Low Rhen | PR | 1226: Renamed from Altena-Berg 1299: Acquired Arenberg 1328: Partitioned into itself and Mark-Arenberg 1391: To Cleves 1394: To Cleves-Mark 1521: To Jülich-Cleves-Berg 1609: Extinct; War of Jülich Succession between Brandenburg and Palatinate-Neuburg 1614: To Brandenburg 1807: To France 1808: To Berg 1813: To Prussia |
| Mark-Arenberg (Marck-Arenberg) | County | Low Rhen | WE | 1328: Partitioned from Mark 1454: Partitioned into itself and Mark-Rochefort 1547: To Ligne by marriage; who assumed the name Arenberg |
| Mark-Rochefort (Marck-Rochefort) | County | n/a | n/a | 1454: Partitioned from Mark-Arenberg 1544: Extinct; to Louis of Stolberg-Stolberg, founder of line Stolberg-Rochefort |
| Mark-Schleiden (Marck-Schleiden) | County | Low Rhen | WE | 1593: Philip of Marck inherited part of Manderscheid-Schleiden-Kerpen, assumed the name Mark-Schleiden 1774: Extinct; to Arenberg |
 Marmoutier (Maursmünster) | Abbacy | Upp Rhen | SP | by 659: Formed 659: Imperial immediacy 1648: To France 1789: Suppressed |
 Martinstein | Lordship | n/a | n/a | Formerly to Daun 1340: To the Archbishopric of Mainz 1353: Enfeoffed to Grasewege 1389: Enfeoffed to Merxheim c. 1555: Enfeoffed to Hunoltstein and Sickingen 1655: Sovereignty to Schönborn 1660: Enfeoffed to Weyers-Leyen and Ebersberg 1716: Sovereignty to Baden 1771: Ebersberg fief to Baden 1795: To France 1815: To Prussia |
 Massa and Carrara (Malaspina) | Marquisate 1568: Principality 1662: Duchy of Massa and Principality of Carrara | n/a | n/a | 1473: Formed when Massa acquired Carrara 1568: HRE Prince 1664: HRE Duke 1796: To the Cispadane Republic 1797: To the Cisalpine Republic 1802: To Italy 1815: Restored 1829: To Modena and Reggio |
 Matsch | Barony | n/a | n/a | 12th Century: Formed 1278: Acquired Tarasp 1344: Acquired Castels 1348: Lost Chiavenna, Puschlav and Bormio to Milan 1365?: Acquired Greifenstein 1372: Sold Malans to Underwegen 1394: Lost Greifenstein to the Bishopric of Chur 1400: Acquired Steinsberg 1421: Lost Advocacy of Marienberg and Müstair to the Tyrol 1464: Sold Tarasp to the Tyrol 1487: Under Imperial Ban 1496: Sold Castels to Austria 1504: Extinct; remaining territories to Trapp |
 Maulbronn | Abbacy | Swab | SP | 1147: Established with imperial immediacy 1504: Made fief of Württemberg 1534: Abbey suppressed 1548: Abbey restored as fief of Württemberg 1807: Secularised and suppressed |
 Mechelen (Malines) | Lordship 1490: County (title remained "Lord") | Burg | n/a | 910: Fief of Bishop of Liège 1333: To Flanders 1369: To Burgundy 1483: To the Burgundian Netherlands 1516: To the Spanish Netherlands 1713: To the Austrian Netherlands 1795: To France 1815: To the Netherlands 1830: To Belgium |
 Mecklenburg | Principality 1347: Duchy | n/a | n/a | 1167: Obotrite prince became a vassal of Saxony, known then on in Germany as Mecklenburg 1180: Imperial immediacy 1234: Partitioned into itself, Werle, Rostock and Parchim-Richenberg 1255: Acquired Sternberg 1301: Acquired Wismar 1304: Acquired Stargard 1312: Acquired Rostock 1319: Acquired Prignitz and Uckermark 1325: Lost Prignitz and Uckermark 1347: HRE Duke 1352: Partitioned into Mecklenburg-Schwerin and Mecklenburg-Stargard |
| Mecklenburg-Grabow | Duchy | n/a | n/a | c. 1669: Appanage created in Mecklenburg-Schwerin 1747: Inherited Mecklenburg-Schwerin; appanage abolished |
| Mecklenburg-Güstrow | Duchy | Low Sax | PR | 1480: Partitioned from Mecklenburg-Schwerin 1483: Extinct; to Mecklenburg-Schwerin 1520: Partitioned from Mecklenburg-Schwerin 1610: Extinct; to Mecklenburg-Schwerin 1621: Partitioned from Mecklenburg-Schwerin 1628-31: To Wallenstein 1695: Extinct in male line; succession dispute 1701: Ratzeburg and Stargard to Mecklenburg-Strelitz; rest to Mecklenburg-Schwerin |
| Mecklenburg-Mirow | Duchy | n/a | n/a | 1658: Appanage created in Mecklenburg-Schwerin 1675: Extinct; to Mecklenburg-Schwerin |
| Mecklenburg-Schwerin Grand Duke of Mecklenburg, Prince of the Wendes, Schwerin & Ratzeburg, Count of Schwerin, Lord of the Lands of Rostock and Stargard | Duchy 1815: Grand Duchy | Low Sax | PR | 1352: Partitioned from Mecklenburg 1358: Acquired Schwerin 1480: Partitioned into itself and Mecklenburg-Güstrow 1436: Acquired 1/3 of Werle 1520: Partitioned into itself and Mecklenburg-Güstrow 1552: Succession dispute 1556: Given to John Albert I, co-Duke of Mecklenburg-Güstrow 1621: Partitioned into itself and Mecklenburg-Güstrow 1628-31: To Wallenstein 1648: Acquired the Bishopric of Schwerin 1658: Appanage Mecklenburg-Mirow 1669: Appanage Mecklenburg-Grabow created 1815: Grand Duchy |
| Mecklenburg-Stargard | Duchy | n/a | n/a | 1352: Partitioned from Mecklenburg 1408: Partitioned into Mecklenburg-Stargard-Sternberg and Mecklenburg-Stargard-Neubrandenburg 1438: Reunited by Mecklenburg-Stargard-Neubrandenburg 1471: Extinct; to Mecklenburg-Schwerin |
| Mecklenburg-Stargard-Neubrandenburg | Duchy | n/a | n/a | 1408: Partitioned from Mecklenburg-Stargard 1436: Acquired 1/3 of Werle 1438: Renamed to Mecklenburg-Stargard |
| Mecklenburg-Stargard-Sternberg | Duchy | n/a | n/a | 1408: Partitioned from Mecklenburg-Stargard 1436: Acquired 1/3 of Werle 1438: Extinct; to Mecklenburg-Stargard-Neubrandenburg |
| Mecklenburg-Strelitz Grand Duke of Mecklenburg, Prince of the Wendes, Schwerin and Ratzeburg, Count of Schwerin, Lord of the Lands of Rostock and Stargard | Duchy 1815: Grand Duchy | Low Sax | PR | 1701: Created from Ratzeburg and Stargard from Mecklenburg-Güstrow for Adolphus Frederick II 1815: Grand Duke |
 Megen | County | n/a | n/a | 1145: First mentioned; fief of Lower Lotharingia 1190: Imperial immediacy 1420: Extinct; to Dicbier 1469: To Brimeu 1610: To Croÿ 1666: To Velen 1697: To the Palatinate 1728: To Schall von Bell 1794: To France 1800: To the Batavian Republic 1806: To Holland 1810: To France 1815: To the Netherlands |
 Meissen | Bishopric | Upp Sax | EC | 948: Formed 1180: Imperial immediacy 13th Century: HRE Prince of the Empire 1666: To Saxony |
 Meissen | Burgraviate | n/a | n/a | bef. 1006: First mentioned 1170: To Sterker von Wohlsbach 1199: To Werben c. 1350: To Werben-Hartenstein 1388: To Werben-Frauenstein 1426: Acquired by Plauen-Plauen who adopted the style 1466: Lost Plauen, Pausa, Gefell, and Graßlitz to Saxony 1572: Extinct; to Saxony |
 Meissen | Margraviate | n/a | n/a | 965: Partitioned from the Marca Geronis 982: Acquired Merseburg and Zeitz 1002: Lost Lusatia 1247: Acquired Thuringia and the County Palatine of Saxony 1261: Partitioned into itself and Landsberg 1423: Purchased Saxony; henceforth Elector of Saxony |
 Memmingen | Imperial City | Swab | SW | 1286: Free Imperial City 1802: To Bavaria |
| Mergentheim | Commandry of the Teutonic Order | Franc | EC | 1058: First mentioned; property of Hohenlohe 1219: To the Teutonic Order 1527: Main seat of the Grandmaster of the Order 1805: HRE Prince 1809: To Württemberg |
 Merseburg | Bishopric | Upp Sax | EC | 968: Formed 1004: HRE Prince of the Empire 1565: To Saxony 1656: To Saxe-Merseburg 1738: To Saxony 1815: To Prussia |
| Merseburg | Burgraviate | n/a | n/a | c. 920: to Goseck 1004: Title retained by Goseck but not the property |
| Merseburg | Margraviate | n/a | n/a | 965: Partitioned from the Marca Geronis 982: Extinct; to the Margraviate of Meissen |
 Meßkirch (Messkirch) | Lordship | Swab | SC | 1080: First mentioned; to Rohrdorf c. 1210: To Frederick of Waldburg who founded the line Waldburg-Rohrdorf c. 1300: To Waldburg-Meßkirch 1354: To Zimmern 1508: To Zimmern-Meßkirch 1594: To Helfenstein-Gundelfingen 1627: To Fürstenberg-Messkirch 1744: To Fürstenberg 1806: To Baden |
 Metz | Bishopric | Upp Rhen | EC | by 535: Established 945, 1047, 1152: Acquired Metzgau piecemeal 1065: Acquired Saarbrücken 1123: Lost Saarbrücken 1241: Lost Dagsburg 1558: Most to France 1632: All territory of the Bishopric to France 1648: Annexation to France formally recognised |
 Metz | Imperial City | Upp Rhen | RH | 1189: Free Imperial City 1552: To France 1648: Annexation to France formally recognised |
 Michaelsberg (Siegberg) | Abbacy | Low Rhen | RP | 1064: Formed 1512: Imperial immediacy 1676: To Palatinate-Neuburg 1685: To the Palatinate 1802: Suppressed |
 Mindelheim | Lordship 1714: Principality of Mindelheim and Schwabegg | Swab | SC / PR | 1250: First mentioned by 1370: To Teck 1439: To Rechberg-Babenhausen 1467: Sold to Frundsberg 1591: Sold to Fugger-Kirchheim 1598: To Fugger-Glött 1616: To Bavaria 1704: To Churchill-Marlborough; HRE Prince 1714: To Bavaria |
 Minden | Bishopric | Low Rhen | see below | 800: Formed 1180: Imperial immediacy; HRE Prince 1648: Secularized as a Principality for Brandenburg |
| Minden | Principality | Low Rhen | PR | 1648: Secularized from the Bishopric of Minden for Brandenburg 1807: To Westphalia 1815: To Prussia |
 Moers (Mörs) | Lordship c. 1230: County 1706: Principality | Low Rhen | WE | c. 1160: First mention of Lords of Moers; fief of the Archbishopric of Cologne c. 1230: HRE Count 1288: Fief of Cleves 1385: Acquired Friemersheim 1399: Acquired Saarwerden by marriage 1417: Partitioned into itself and Moers-Saarwerden 1488: Seized by the Emperor 1493: To Wied-Runkel 1500: Returned to Moers 1501: Extinct; to Moers-Saarwerden 1510: To Wied-Runkel 1519: To Neuenahr-Bedburg 1584: To Spain 1597: To Neuenahr-Bedburg 1600: To Cleves 1601: To Maurice of Nassau-Orange; united with Nassau-Orange from 1618: Formed 1607: Imperial immediacy 1702: To Prussia 1794: To France 1815: To Prussia |
| Moers-Saarwerden | County | Upp Rhen | WE | 1417: Partitioned from Moers 1527: Extinct; to Nassau-Saarbrücken |
| Mondsee | Abbacy | ? | SP | 748: Formed 788: Imperial immediacy 831: To the Bishopric of Regensburg 1142: Regained imperial immediacy 1506: Fief of Austria 1791: Suppressed |
 Mons (Bergen) | County | n/a | n/a | 980: Partitioned from Hainaut 1071: Extinct; to Hainaut |
 Monschau (Montjoie) | Barony | n/a | n/a | 1221: Mentioned as a property of Limburg 1226: To Limburg-Monschau 1262: To Valkenburg 1354: To Schönau-Schönforst 1433: To Jülich |
 Montbéliard (Mömpelgard) | County | Swab | PR | 10th Century: First mentioned 1105: To Scarponnois 1163: To Montfaucon who assumed the title Montbéliard 1397: To Württemberg by marriage 1793: To France |
| Montechiarugolo | County | 1180: Partitioned from Guastalla 1612: Acquired by the Duchy of Parma | ||
 Montfort | County | n/a | n/a | 1180: Partitioned from Tübingen 1258: Partitioned into Montfort-Feldkirch, Montfort-Bregenz, Montfort-Tettnang, Werdenberg-Heiligenberg and Werdenberg-Sargans |
| Montfort-Bregenz | County | n/a | n/a | 1258: Partitioned from Montfort c. 1290: Sigmaringen sold to Austria 1338: Extinct; to Montfort-Tettnang |
| Montfort-Bregenz-Bregenz | County | Swab | SC | 1482: Partitioned from Montfort-Bregenz-Stadeck 1525: Sold to Austria 1550: Extinct |
| Montfort-Bregenz-Montfort | County | Swab | SC | 1482: Partitioned from Montfort-Bregenz-Stadeck 1515: Extinct; to Montfort-Bregenz-Bregenz |
| Montfort-Bregenz-Peggau (Montfort-Bregenz-Beckach) | County | Swab | SC | 1524: Renamed from Montfort-Bregenz-Pfannberg; fief of Styria 1574: Acquired territory of Montfort-Tettnang-Rothenfels 1581: Sold Liebenfels to Matthias Laymann 1592: Sold Wasserburg to Fugger-Weißenhorn 1576: Partitioned into Montfort-Bregenz-Peggau-Montfort, Montfort-Bregenz-Peggau-Tettnang and Montfort-Bregenz-Peggau-Peggau |
| Montfort-Bregenz-Peggau-Montfort (Montfort-Bregenz-Beckach-Montfort) | County | Swab | SC | 1576: Partitioned from Montfort-Bregenz-Peggau 1590: Extinct; to Montfort-Bregenz-Peggau-Tettnang |
| Montfort-Bregenz-Peggau-Peggau (Montfort-Bregenz-Beckach-Beckach) | County | n/a | n/a | 1576: Partitioned from Montfort-Bregenz-Peggau 1596: Sold Peggau 1617: Extinct |
| Montfort-Bregenz-Peggau-Tettnang (Montfort-Bregenz-Beckach-Tettnang) | County | Swab | SC | 1576: Partitioned from Montfort-Bregenz-Peggau 1657: Acquired Schomburg 1764: Liebenau sold to Weingarten Abbey 1780: Sold to Austria 1787: Extinct |
| Montfort-Bregenz-Pfannberg | County | Swab | SC | 1423: Partitioned from Montfort-Tettnang-Bregenz Elder Line 1437: Extinct; to Montfort-Bregenz-Stadeck 1482: Partitioned from Montfort-Bregenz-Stadeck 1524: Sold Pfannberg to Styria; renamed to Montfort-Bregenz-Peggau |
| Montfort-Bregenz-Stadeck | County | n/a | n/a | 1423: Partitioned from Montfort-Tettnang-Bregenz Elder Line 1482: Partitioned into Montfort-Bregenz-Bregenz, Montfort-Bregenz-Pfannberg and Montfort-Bregenz-Montfort |
| Montfort-Feldkirch | County | n/a | n/a | 1258: Partitioned from Montfort 1302: Partitioned into itself and Montfort-Tosters 1375: Sold to Austria 1390: Extinct |
| Montfort-Tettnang | County | n/a | n/a | 1258: Partitioned from Montfort 1287: Sold Scheer to Austria 1314: Acquired Scheer and Friedberg 1331: Acquired Rothenfels 1354: Partitioned into Montfort-Tettnang-Tettnang and Montfort-Tettnang-Bregenz |
| Montfort-Tettnang-Bregenz | County | n/a | n/a | 1354: Partitioned from Montfort-Tettnang 1362: Acquired Pfannberg 1379: Partitioned into Montfort-Tettnang-Bregenz Elder Line and Montfort-Tettnang-Bregenz Younger Line |
| Montfort-Tettnang-Bregenz Elder Line | County | n/a | n/a | 1379: Partitioned from Montfort-Tettnang-Bregenz 1423: Partitioned into Montfort-Bregenz-Pfannberg and Montfort-Bregenz-Stadeck |
| Montfort-Tettnang-Bregenz Younger Line | County | n/a | n/a | 1379: Partitioned from Montfort-Tettnang-Bregenz 1458: Sold to Austria |
| Montfort-Tettnang-Langenargen | County | n/a | n/a | 1439: Partitioned from Montfort-Tettnang-Tettnang 1445: Extinct; to Montfort-Tettnang-Rothenfels |
| Montfort-Tettnang-Rothenfels | County | Swab | SC | 1439: Partitioned from Montfort-Tettnang-Tettnang 1567: Rothenfels sold to Königsegg-Aulendorf 1574: Extinct; to Montfort-Bregenz-Peggau |
| Montfort-Tettnang-Tettnang | County | Swab | SC | 1354: Partitioned from Montfort-Tettnang 1386: Acquired Wasserburg 1399: Acquired Oberstaufen 1414: Scheer and Friedberg to Zillenhard 1420: Acquired Bludenz 1437: Acquired Davos and Prättigau 1439: Partitioned into itself, Montfort-Tettnang-Rothenfels and Montfort-Tettnang-Langenargen 1526: Extinct; to Montfort-Tettnang-Rothenfels |
| Montfort-Toggenburg | County | n/a | n/a | 1436: Henry V of Montfort-Tettnang-Tettnang obtained part of Toggenburg 1483: Extinct; to Montfort-Tettnang-Tettnang |
| Montfort-Tosters | County | n/a | n/a | 1302: Partitioned from Montfort-Feldkirch 1359: Extinct; to Montfort-Feldkirch |
 Mosbach | Imperial City | n/a | n/a | 1241: Free Imperial City 1297: To Breuberg 1367: To the Palatinate 1410: To Palatinate-Mosbach 1448: To Palatinate-Mosbach-Neumarkt 1499: To the Palatinate 1803: To Leiningen 1806: To Baden |
 Mühlhausen | Imperial City | Low Sax | RH | 1251: Free Imperial City 1802: To Prussia 1807: To Westphalia 1815: To Prussia |
 Mulhouse (Mülhausen) | Imperial City | Upp Rhen | RH | 1275: Free Imperial City 1437: Acquired Illzach and Modenheim 1515: Ally of the Swiss Confederation 1648: Left the Empire as a Swiss ally 1798: To France |
 Münchenroth (Mönchsrot)See: Rot an der Rot | Abbacy | |||
 Münster (Munster) | Bishopric | Low Rhen | EC | c. 795: Formed 1122: Acquired Kappenberg as fief of Saxony 1134: HRE Prince of the Empire c. 1170: Acquired Stromberg as fief of Saxony 1180: Imperial immediacy 1252: Acquired Vechta 1269: Acquired Horstmar 1400: Acquired Ahaus 1803: Secularized and divided between Prussia, Arenberg, Looz-Corswarem, Salm-Kyrburg, Salm-Salm and Croÿ |
 Munster (Münster im Gregoriental) | Imperial City | Upp Rhen | RH | 1354?: Free Imperial City 1648: To France |
 Murbach | Abbacy | Upp Rhen | RP | 722: Formed 792: Imperial immediacy 1648: To France 1789: Secularised |
| Muri | Abbacy | n/a | n/a | 1027: Formed Abbey never held immediate territory 1648: To Switzerland 1701: HRE Prince of the Empire |
 Myllendonk (Millendonk) | Lordship | Low Rhen | WE | 1166: First mentioned 1268: Made fief of Guelders 1279: Fief of the Archbishopric of Cologne 1297: Sold to Reifferscheid-Myllendonk as fief of Cologne c. 1300: Extinct 1346/50: To Myllendonk-Mirlaer as fief of Cologne 1612: To Bronckhorst-Batenberg as fief of Cologne 1641: To Croÿ-Myllendonk as fief of Cologne 1683: To Croÿ as fief of Cologne 1694: To Berlepsch as fief of Cologne 1700: To Ostein; imperial immediacy, Lower Rhenish-Westphalian Circle 1794: To France 1815: To Prussia |
