Stephen I, also known as King Saint Stephen (Hungarian: Szent István király [ˌsɛnt ˈiʃtvaːn kiraːj]; Latin: Sanctus Stephanus; Slovak: Štefan I. or Štefan Veľký; c. 975 – 15 August 1038), was the last grand prince of the Hungarians between 997 and 1000 or 1001, and the first king of Hungary from 1000 or 1001 until his death in 1038. The year of his birth is uncertain, but many details of his life suggest that he was born in, or after, 975, in Esztergom. He was given the pagan name Vajk at birth, but the date of his baptism is unknown. He was the only son of Grand Prince Géza and his wife, Sarolt, who was descended from a prominent family of gyulas. Although both of his parents were baptized, Stephen was the first member of his family to become a devout Christian. He married Gisela of Bavaria, a scion of the imperial Ottonian dynasty.
After succeeding his father in 997, Stephen had to fight for the throne against his relative, Koppány, who was supported by large numbers of pagan warriors. He defeated Koppány with the assistance of foreign knights including Vecelin, Hont and Pázmány, and native lords. He was crowned on 25 December 1000 or 1 January 1001 with a crown sent by Pope Sylvester II. In a series of wars against semi-independent tribes and chieftains—including the Black Hungarians and his uncle, Gyula the Younger—he unified the Carpathian Basin. He protected the independence of his kingdom by forcing the invading troops of Conrad II, Holy Roman Emperor, to withdraw from Hungary in 1030.
