Leszek I the White

Leszek the White
19th century portrait by Jan Matejko.
High Duke of Poland
Reign	1194–1198 1199–1202 1206–1210 1211–1227
Predecessor	Casimir II the Just
Successor	Władysław III Spindleshanks
Duke of Sandomierz
Reign	1194–1227
Predecessor	Casimir II the Just
Successor	Władysław III Spindleshanks
Duke of Masovia
Reign	1194–1200
Predecessor	Casimir II the Just
Successor	Konrad I
Born	c. 1184/85
Died	24 November 1227 (age c. 42–43) Gąsawa, Kujawy, Poland
Spouse	Grzymisława
Issue	Salomea Helena Bolesław V the Chaste
House	House of Piast
Father	Casimir II the Just
Mother	Helen of Znojmo

Leszek the White (Polish: Leszek Biały; ca. 1184/85 – 24 November 1227) was Prince of Sandomierz and High Duke of Poland during 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.

Leszek was the third or fourth but eldest surviving son of Casimir II the Just and his wife Helen of Znojmo.

When Casimir II died on 5 May 1194, Leszek was only nine or ten years old. K. Jasiński, writing in 2001, puts his birthyear in 1184–85, while older historiography claimed 1186–87. The regency was exercised by his mother Helen, who counted with the help of Mikołaj Gryfita, wojewoda of Kraków and Fulko, Bishop of Kraków.

However, Leszek's uncle Mieszko III the Old – who had been ruler of Kraków (r. 1173–77) and was deposed after a national rebellion against him – refused to accept this, and with the help of powerful Lesser Poland families, decided to reconquer Kraków.

The war began in 1195. On the side of Leszek and his youngest brother Konrad fought the nobility of Kraków, Sandomierz, and probably the Rurikid Roman, Prince of Vladimir-in-Volhynia. Mieszko III the Old was able to negotiate with his Silesian relatives, Mieszko Tanglefoot, Duke of Racibórz and his nephew Jarosław, Duke of Opole, who promised to send food to him during the campaign.