Leszek of Masovia (Polish: Leszek Bolesławowic ) (ca. 1162–1186) was the second Duke of Masovia and Kuyavia from 1173 until his death.

He was the second but only surviving son of Bolesław IV the Curly, High Duke of Poland by his first wife Viacheslava, daughter of St. Vsevolod, Prince of Novgorod and Pskov. Once it was thought that his mother was Maria, Bolesław IV's second wife, a fact which was shown in several web sources;^[1][2][3] however, after the discovery of coins where Leszek called himself son of Bolesław and Anastasia (the Greek or Latin equivalent of Viacheslava's name), this theory proved to be inaccurate.^[4] He was named either thanks to the courtly tradition preserved by Gallus Anonymus in his Cronicae Polonorum or after the eldest full-brother of his father, Leszek, who died young around 1131.

  Life

The death of his older brother Bolesław in 1172 leave him as the only heir of his father. High Duke Bolesław IV (reportedly devastated by his first born son's death) died one year later (3 April 1173), leaving Masovia and Kuyavia to Leszek, at the age of eleven or less. The overlordship of Poland (who included the control over Kraków and Gniezno), was taken by the eldest surviving brother of Bolesław IV, Mieszko III the Old.

Leszek began his rule under the guardianship of his youngest uncle, Casimir II the Just. According to the Bishop of Kraków and chronicler Wincenty Kadłubek, the young Duke of Masovia suffered of an extremely poor health and even after he formally took the government of his domains in 1177, the effective rule was handed by the magnate Żyron.

Since he take the control over his domains, Leszek's policy was based on a close cooperation with Casimir II the Just, whose interests in Masovia (after he took the title of High Duke in 1177) were represented by the magnate Żyron. A manifestation of good relations with Casimir II was the participation of Leszek in the war against Prince Volodar of Minsk, who in 1180 captured Brest, who belonged to Leszek's brother-in-law, Vasilko Iaropolkovich. After a long and exhausting war, Brest ultimately wasn't recovered, and Vasilko gave all the rights over this land to Leszek (the region was annexed to Poland only by Casimir II in 1191, after he deposed Mieszko III and took the title of High Duke).

In 1184 Leszek unexpectedly changed his dynastic politics. For unknown reasons, during a meeting in Płock, he made an agreement with his uncle Mieszko III the Old, who was declared his heir if he died without issue; also, Leszek called his cousin Mieszko the Younger (Mieszko III's son) and entrusted him with the government of his Duchy. Probably the real purprose of the appointment of Mieszko the Younger as governor of Masovia was prepared him as Leszek's successor after his death.

However, the inheritance of Masovia and Kuyavia by the Greater Poland branch never happen; one year later (1185), Leszek changed his testament again and named his uncle Casimir II as his successor. The main reason of this attitude maybe were the rude and harsh proceedings of the Greater Poland Duke.

Leszek died unmarried and childless in 1186; he was probably buried in the Płock Cathedral.^[5] Under his will, his heir was Casimir II the Just, but Mieszko III managed to conquer Kuyavia, who was given to his son Bolesław. The High Duke only could take Masovia, but thanks to this inheritance, he became in the most powerful ruler of Poland.

  References