Grand Prince Géza of the Árpád dynasty was the nominal overlord of all seven Magyar tribes but in reality ruled only part of the united territory. He aimed to integrate Hungary into Christian Western Europe by rebuilding the state according to the Western political and social models. Géza founded the Hungarian town in 972 on four moorland islands between the Gaja stream and its tributary, the Sárvíz, one of the most important Hungarian tributaries of the Danube. He also had a small stone castle built. Székesfehérvár was first mentioned in a document by the Bishopric of Veszprém, 1009, as "Alba Civitas".