In the north, the Republic of Novgorod prospered because it controlled trade routes from the River Volga to the Baltic Sea. As Kievan Rus' declined, Novgorod became more independent. A local oligarchy ruled Novgorod; major government decisions were made by a town assembly, which also elected a prince as the city's military leader. In the 12th century, Novgorod acquired its own archbishop Ilya in 1169, a sign of increased importance and political independence, while about 30 years prior to that in 1136 in Novgorod was established a republican form of government - elective monarchy. Since then Novgorod enjoyed a wide degree of autonomy although being closely associated with the Kievan Rus.