Andrzej Jastrzębiec , also known as Andrzej Wasilko or Andrzej Polak, (died 1398) was a Polish

Poland

Poland , officially the Republic of Poland , is a country in Central Europe bordered by Germany to the west; the Czech Republic and Slovakia to the south; Ukraine, Belarus and Lithuania to the east; and the Baltic Sea and Kaliningrad Oblast, a Russian exclave, to the north...

 Catholic priest and diplomat, a first bishop of Seret

Siret

Siret is a town in Romania, Suceava County, one of the oldest towns in, and a former capital of, the former principality of Moldavia. It is located 2 km from the border with Ukraine, being one of the main border passing points in the North of the country, having both a road border post and a...

 and of Vilnius

Vilnius

Vilnius is the capital of Lithuania, and its largest city, with a population of 560,190 as of 2010. It is the seat of the Vilnius city municipality and of the Vilnius district municipality. It is also the capital of Vilnius County...

. Little is known of his youth and he might have been born to a peasant family. He joined the Franciscans and quickly rose through the ranks of the order.

The first verified mention of Andrzej Jastrzębiec dates back to 1354, when he was listed among the parochs in Mazovia

Mazovia

Mazovia or Masovia is a geographical, historical and cultural region in east-central Poland. It is also a voivodeship in Poland.Its historic capital is Płock, which was the medieval residence of first Dukes of Masovia...

. After a brief time spent as a missionary in the pagan Grand Duchy of Lithuania

Grand Duchy of Lithuania

The Grand Duchy of Lithuania was a European state from the 12th /13th century until 1569 and then as a constituent part of Polish-Lithuanian Commonwealth until 1791 when Constitution of May 3, 1791 abolished it in favor of unitary state. It was founded by the Lithuanians, one of the polytheistic...

, he moved to the royal court of Hungary

Kingdom of Hungary

The Kingdom of Hungary comprised present-day Hungary, Slovakia and Croatia , Transylvania , Carpatho Ruthenia , Vojvodina , Burgenland , and other smaller territories surrounding present-day Hungary's borders...

, where he became the confessor to Queen Elisabeth of Poland and Hungary

Elisabeth of Poland

Elisabeth of Poland was Queen consort of Hungary and regent of Poland. She is also known as Elisabeth of Kujavia and Elisabeth Piast.-Early life:...

. From there he set off to Moldavia

Moldavia

Moldavia is a geographic and historical region and former principality in Eastern Europe, corresponding to the territory between the Eastern Carpathians and the Dniester river...

, where he spent several years as a missionary. As an effect of his mission, on July 31, 1370, a new bishopric of Seret was created and the following year Andrzej became its first bishop.

Already in 1372 he moved back to Poland, where he took over the diocese of Halych. Between 1376 and 1386 he served as an auxiliary bishop in the diocese of Gniezno. In 1388, king Władysław II of Poland

Jogaila

Jogaila, later 'He is known under a number of names: ; ; . See also: Jogaila : names and titles. was Grand Duke of Lithuania , king consort of Kingdom of Poland , and sole King of Poland . He ruled in Lithuania from 1377, at first with his uncle Kęstutis...

 sent Andrzej with a mission to baptise Lithuania. Following the creation of a diocese of Vilnius

Archdiocese of Vilnius

The Roman Catholic Metropolitan Archdiocese of Vilnius is an ecclesiastical territory or diocese of the Roman Catholic Church in Lithuania. Established as the Diocese of Vilnius in the 14th century, it was elevated to the rank of a metropolitan archdiocese by Pope Pius XI on October 28, 1925...

, Andrzej became its first bishop. He died November 14, 1398 and was succeeded by his deputy, Jakub Plichta.