Red Ruthenia, or Red Rus or Red Russia, is a term used since the Middle Ages for the south-western principalities of the Kievan Rus', namely the Principality of Peremyshl and the Principality of Belz. Nowadays the region comprises parts of western Ukraine and adjoining parts of south-eastern Poland. It has also sometimes included parts of Lesser Poland, Podolia, Right-bank Ukraine and Volhynia. Centred on Przemyśl and Belz, it has included major cities such as: Chełm, Zamość, Rzeszów, Krosno and Sanok, as well as Lviv and Ternopil.
The Principality or, from 1253, Kingdom of Galicia–Volhynia, also known as the Kingdom of Ruthenia or Kingdom of Rus/Russia, was a medieval state in Eastern Europe which existed from 1199 to 1349. Its territory was predominantly located in modern-day Ukraine, with parts in Belarus, Poland, Moldova, and Lithuania. Along with Novgorod and Vladimir-Suzdal, it was one of the three most important powers to emerge from the collapse of Kievan Rus'.
Leszek the White was Prince of Sandomierz and High Duke of Poland in the years 1194–1198, 1199, 1206–1210, and 1211–1227. During the early stages of his reign, his uncle Duke Mieszko III the Old and cousin Władysław III Spindleshanks, from the Greater Polish branch of the royal Piast dynasty, contested Leszek's right to be High Duke.
Vsevolod IV Svyatoslavich the Red or Vsevolod Chermnyi was Grand Prince of Kiev. He was also Prince of Chernigov (1204–1206/1208) and Belgorod Kievsky (1205). His baptismal name was Daniil.
Pobóg is a Polish coat of arms that was used by many noble families in medieval Poland and later under the Polish–Lithuanian Commonwealth.
Bełz Voivodeship was a unit of administrative division and local government in the Poland from 1462 to the Partitions of Poland in 1772–1795. Together with the Ruthenian Voivodeship it was part of Red Ruthenia, Lesser Poland Province. The voivodeship was created by King Kazimierz Jagiellonczyk, and had four senators in the Senate of the Commonwealth.
Mstislav Mstislavich the Daring, also called the Able, was a prince of Tmutarakan and Chernigov, one of the princes from Kievan Rus' in the decades preceding the Mongol invasions.
Leszek of Masovia was a Polish prince from the Piast dynasty, the Duke of Masovia from 1173 until his death. He was the only son of Bolesław IV the Curly, Duke of Masovia and High Prince of Poland, to survive his father. After his father's death he inherited Masovia. At the beginning, Leszek ruled under the guardianship of his uncle Casimir II the Just. He was a man of poor health. For a short time he supported his other uncle, Mieszko III the Old, but later decided to reconcile with Casimir II, who after Leszek's death inherited his duchy.
The Battle of Zawichost (1205) was fought between Roman the Great of Galicia-Volhynia and Leszek the White of Sandomierz, along with his brother Konrad I of Masovia. After declaring war and invading Lesser Poland, Roman and his forces (druzhina) were ambushed by the Poles in the vicinity of Zawichost by the river Vistula (Wisła). In the tumult that followed, Roman was killed and the Polish victory would lead to growing power for Leszek and Konrad, while triggering a war of succession in Galicia–Volhynia. The battle is considered one of the greatest victories of medieval Poland.
Mstislav II Svyatoslavich was a Kievan Rus' prince. His baptismal name was Panteleymon. He was probably prince of Kozelsk (1194–1223), of Novgorod-Seversk (1206–1219), and of Chernigov (1215/1220–1223). He was killed in the Battle of the Kalka River.
Casimir II the Just was a Lesser Polish Duke of Wiślica from 1166 to 1173, and of Sandomierz after 1173. He became ruler over the Polish Seniorate Province at Kraków and thereby High Duke of Poland in 1177; a position he held until his death, though interrupted once by his elder brother and predecessor Mieszko III. In 1186 Casimir also inherited the Duchy of Masovia from his nephew Leszek, becoming the progenitor of the Masovian branch of the royal Piast dynasty, and great-grandfather of the later Polish king Władysław I the Elbow-high. The honorific title "the Just" was not contemporary and first appeared in the 16th century.
Agnes of Poland was a member of the House of Piast and by marriage princess of Pereyaslavl and Volynia and grand princess of Kiev since 1168.
The Principality of Volhynia was a western Kievan Rus' principality founded by the Rurikid prince Vsevolod in 987 centered in the region of Volhynia, straddling the borders of modern-day Ukraine, Belarus, and Poland. From 1069 to 1118, it belonged to Izyaslavichi who primarily ruled from Turov. After losing Turov to Monomakhovichi in 1105, the descendants of Iziaslav Yaroslavovich for a few years continued to rule in Volhynia. From 1154 to 1199, the Principality was referred to as the Principality of Volodymyr when the Principality of Lutsk (1154–1228) was separated.
Duchy of Belz or Principality of Belz was a duchy, formed in the late 12th century in Kievan Rus. During its history the duchy was a constituent part of some other political entities such as the Kingdom of Rus, the Kingdom of Hungary, Duchy of Masovia when eventually in the late 14th century was incorporated into Poland becoming later the Bełz Voivodeship.
Vladimir II Yaroslavich was a Rus’ prince. He was prince of Halych.
The Miecław's State was a state located in Masovia with capital in Płock. It was formed around 1037 by Miecław by breaking away from Duchy of Poland during the crisis inside the country. It existed until 1047, when Casimir I the Restorer, duke of Poland, reconquered the state into Duchy of Poland.
Duchy of Wiślica was a district principality and a fiefdom within the Kingdom of Poland. It was formed in 1166 from the territories of the Duchy of Sandomierz, following its fragmentation onto three parts. The state was ruled by Casimir II the Just, and it existed until 1173, when Casimir had assumed the throne of the Duchy of Sandomierz, uniting two states together. Its capital was Wiślica and it was located in the southern Sandomierz Land in the southeastern corner of the Kingdom of Poland. The state was later shortly reestablished in 1230 by Grzymisława of Łuck who ruled it as a regent in the name of her son, Bolesław V the Chaste. In 1234, they had become rulers of the whole Duchy of Sandomierz, with that year being the last mention of the duchy in the documents.
Miecław's Rebellion was a military conflict fought from c. 1037 to 1047 between the Duchy of Poland under Casimir I the Restorer and its ally, Kievan Rus', led by Yaroslav the Wise, against the forces of Miecław, the self-proclaimed leader of a breakaway state, who was allied with the Duchy of Pomerelia and the Yotvingians. The war began with the declaration of independence of Miecław's State in Masovia from the Duchy of Poland in c. 1037. It ended in 1047 with Miecław's death and the state being reconquered by Poland.
Bolesław II the Bold's expedition to Kiev in 1069 aimed to assert Polish influence in the region, mirroring the conquests of his predecessor, Bolesław the Brave. Bolesław II the Bold occupied Kiev where he put the allied Iziaslav I of Kiev on the throne and on the way back occupied Przemyśl and annexed Cherven Cities to Poland.
Mikołaj Gryfita was a Voivode of Kraków from 1176 to 1202, and acted as a regent from 1198 to 1199 on behalf of Prince Leszek the White.
Kingdom of Poland 
