In the 11th century and the 12th century, the princes and their retinues, which were a mixture of Slavic and Scandinavian elites, dominated the society of Kievan Rus'. Leading soldiers and officials received income and land from the princes in return for their political and military services. Kievan society lacked the class institutions and autonomous towns that were typical of Western European feudalism. Nevertheless, urban merchants, artisans and labourers sometimes exercised political influence through a city assembly, the veche (council), which included all the adult males in the population. In some cases, the veche either made agreements with their rulers or expelled them and invited others to take their place. At the bottom of society was a stratum of slaves. More important was a class of tribute-paying peasants, who owed labour duty to the princes. The widespread personal serfdom characteristic of Western Europe did not exist in Kievan Rus'.