The Treaty of Kępno (Polish : umowa kępińska, układ w Kępnie) was an agreement between the High Duke of Poland and Wielkopolska Przemysł II and the Duke of Pomerania Mestwin II (sometimes rendered as "Mściwój") signed on February 15, 1282, which transferred the suzerainty over Gdańsk Pomerania (Pomeralia) to Przemysł. As a result of the treaty Przemysł adopted the title dux Polonie et Pomeranie (Duke of Poland and Pomerania).
Mestwin, per the agreement, retained de facto control over the province until his death in 1294, at which time Przemysł, who was already the de jure ruler of the territory, took it over in practice.According to some sources, it's possible that Mestwin kept full control of the province and the agreement merely stipulated that whichever ruler lived longer would take over the others territory. The treaty was, per custom, affirmed and approved by an assembly of nobles of both Pomerania and Wielkopolska.
The merger of Gdańsk Pomerania with Przemysł's other Polish provinces of Poznań, Wielkopolska, and Kraków was an important step in the process of reunification of Poland,after its feudal break up, which took place after the death of Bolesław III Wrymouth in 1138. The year after taking full control of Pomerania, Przemysł was crowned as king of Poland in Kraków. In the following year (1296) however, he was assassinated by agents of the Margrave of Brandenburg and some Polish nobles (the Nałęcz family), as both parties opposed the rise of a strong central power in Poland. Przemysł's realm, including Pomerania, became the subject of a civil war between Wenceslaus II of Bohemia and Władysław I the Elbow-high, both of whom at some point crowned themselves as kings of Poland.
The immediate effect of the treaty was that Mestwin and Przemysł began to carry out a single foreign policy, particularly in regard to Brandenburg and Western Pomerania. Additionally, Przemysł appointed several of his trusted men from Wielkopolska to offices in Gdansk and the surrounding area.
The treaty was followed up with several subsequent extensions and agreements. These included meetings in Nakło (1284), Słupsk (1287), Rzepka (1288) and once again Nakło (1291). The meeting in Słupsk in November 1284 was particularly important as it was also attended by the Duke of Szczecin-Pomerania (one of the duchies of Western Pomerania), Bogusław IV of the Griffins dynasty. The three rulers (Przemysł, Mestwin and Bogusław) concluded a mutual-defense alliance, directed against the expansionistic policies of Brandenburg, and it was agreed that Bogusław was to inherit Pomerania in case if both Przemysł and Mestwin died without heirs. This alliance was reaffirmed at the meeting in 1291 at Nakło.Despite the fact that Bogusław outlived both Mestwin and Przemysł, events on the ground and subsequent political developments, such as the struggle between Wenceslaus and Władysław the Elbow-high, meant that the provisions of the Nakło agreement were never implemented and Bogusław did not succeed come to acquire control over Pomeralia.
As part of the treaty Przemysł also granted the town of Kępno municipal rights, based on those of Kalisz.
Władysław I Łokietek, in English known as the "Elbow-high" or Ladislaus the Short, was King of Poland from 1320 to 1333, and duke of several of the provinces and principalities in the preceding years. He was a member of the royal Piast dynasty, the son of Duke Casimir I of Kuyavia, and great-grandson of High-Duke Casimir II the Just.
Pomerelia, also known as Eastern Pomerania, Vistula Pomerania, prior to World War II also known as Polish Pomerania, is a historical sub-region of Pomerania on the southern shore of the Baltic Sea. The designation of Gdańsk Pomerania, is largely coextensive with Pomerelia, but slightly narrower, as it does not cover the Chełmno Land.
Sławno is a town on the Wieprza river in Middle Pomerania region, north-western Poland, with 12,511 inhabitants (2019). It is the administrative seat of Gmina Sławno, though not part of it. The town is also the capital of Sławno County in West Pomeranian Voivodeship since 1999, previously in Słupsk Voivodeship (1975–1998).
Przemysł II was the Duke of Poznań from 1257–1279, of Greater Poland from 1279 to 1296, of Kraków from 1290 to 1291, and Gdańsk Pomerania (Pomerelia) from 1294 to 1296, and then King of Poland from 1295 until his death. After a long period of Polish high dukes and two nominal kings, he was the first to obtain the hereditary title of king, and thus to return Poland to the rank of kingdom. A member of the Greater Poland branch of the House of Piast as the only son of Duke Przemysł I and the Silesian princess Elisabeth, he was born posthumously; for this reason he was brought up at the court of his uncle Bolesław the Pious and received his own district to rule, the Duchy of Poznań in 1273. Six years later, after the death of his uncle, he also obtained the Duchy of Kalisz.
The Duchy of Greater Poland was a district principality in Greater Poland that was a fiefdom of the Kingdom of Poland. It was formed in 1138 from the territories of the Kingdom of Poland, following its fragmentation started by the testament of Bolesław III Wrymouth. In 1177, the state broke had separated into the duchies of Poznań, Gniezno and Kalisz, and united again in 1279, lasting in that form until 1320, when it was incorporated back into the Kingdom of Poland. Its capital was Poznań.
Przemysł I, a member of the Piast dynasty, was Duke of Greater Poland from 1239 until his death, from 1241 with his brother Bolesław the Pious as co-ruler. He was able to re-acquire large parts of Greater Poland, ruling as Duke of Poznań and Gniezno from 1247 and, upon several inheritance conflicts with his brother, as Duke of Poznań and Kalisz from 1249, sole Duke of Greater Poland from 1250, and Duke of Poznań from 1253 until his death.
Bolesław the Pious was a Duke of Greater Poland during 1239–1247, Duke of Kalisz during 1247–1249, Duke of Gniezno during 1249–1250, Duke of Gniezno-Kalisz during 1253–1257, Duke of whole Greater Poland and Poznań during 1257–1273, in 1261 ruler over Ląd, regent of the Duchies of Mazovia, Płock and Czersk during 1262–1264, ruler over Bydgoszcz during 1268–1273, Duke of Inowrocław during 1271–1273, and Duke of Gniezno-Kalisz from 1273 until his death.
Mestwin II was a Duke of Pomerelia, member of the Samborides dynasty. He ruled Pomerelia as a sole ruler from 1273 to 1294.
Swietopelk II, also Zwantepolc II or Swantopolk II,, sometimes known as the Great, was the ruling Duke of Pomerelia-Gdańsk from 1215 until his death. He was the first member of the Samborides to style himself dux from 1227 onwards.
Pelplin is a town in northern Poland, in the Tczew County, Pomeranian Voivodship. Population: 8,320 (2009).
The Duchy of Eastern Pomerania, also known as the Duchy of Pomerelia, was a duchy centred on Pomerelia, with Gdańsk as its capital.
The Samborides or House of Sobiesław were a ruling dynasty in the historic region of Pomerelia. They were first documented about 1155 as governors (princeps) in the Eastern Pomeranian lands serving the royal Piast dynasty of Poland, and from 1227 ruled as autonomous princes until 1294, at which time the dynasty died out. The subsequent war for succession between the Polish Piast dynasty, the Imperial Margraviate of Brandenburg and the State of the Teutonic Order resulted in the Teutonic takeover of Gdańsk (Danzig) in 1308.
The Treaty of Arnswalde was signed on 1 April 1269 between three Brandenburgian margraves, the Ascanians John II, Otto IV and Conrad, and Duke Mestwin II of Pomerelia in Arnswalde.
The Polish–Teutonic War (1326–1332) was the war between the Kingdom of Poland and the State of the Teutonic Order over Pomerelia, fought from 1326 to 1332.
The Schlawe and Stolp Land, also known as Słupsk and Sławno Land, is a historical region in Pomerania, centered on the towns of Sławno (Schlawe) and Słupsk (Stolp) in Farther Pomerania, in present-day Poland.
Pomerania during the Late Middle Ages covers the history of Pomerania in the 14th and 15th centuries.
The Gąsawa massacre was an attack on the night of 23 / 24 November 1227 during a council of Polish Piast dukes which was being held near the village of Gąsawa in Kuyavia, Poland. The High Duke of Poland, Leszek the White, was assassinated, and Duke Henry the Bearded of Silesia was gravely wounded.
Wartislaw II of Gdańsk was a duke from the Samboride dynasty. From 1266 to 1270, he was the duke of the Duchy of Gdańsk, and also, briefly in 1269, the duke of the Duchy of Świecie.
The civil war in Pomerelia was a military conflict in Pomerelia fought from 1269 to 1272. The conflict had begun between members of the Samboride dynasty, with Mestwin II, ruler of the Duchy of Świecie fighting against Wartislaw II of Gdańsk, ruler of the Duchy of Gdańsk, and Sambor II, ruler of the Duchy of Lubiszewo. In 1270, Mestwin had conquered their states, unifying the Duchy of Pomerelia under his rule. Wartislaw II and Sambor II continued to fight from exile, aided by the Duchy of Inowrocław and the State of the Teutonic Order, while Mestwin had allied with Bolesław the Pious, ruler of the Duchy of Greater Poland. In 1271, the war was joined by the Margraviate of Brandenburg who attempted to conquer the Duchy of Pomerelia. The war ended in January 1272, with Mestwin II's victory, establishment of the Duchy of Pomerelia, and partition of the Duchy of Inowrocław between Pomerelia and Greater Poland.