The voyi (singular voi or voy) formed a category of armed forces in Kievan Rus', ancient Rus'.
Unlike the standing force (the ''druzhina''), the voi force was drafted from a local population. Alongside the druzhina, the voyi formed a basis of an army in Rus'. A prince (knyaz) would appoint a ''voivode'' (from ''voi'' - "army", and ''vode'' - "to lead", meaning "warlord") to command them.
{{East-Slavic-hist-stub
Society of Kievan Rus'
Military history of Russia