In case of emergency
The Kievan Rus had no standing army apart from small "druzhina" (дружи́на), a permanent group of personal guards for the local ruler (knyaz, "prince"); an individual member of such a unit called a "druzhinnik" (дружи́нник). In case of emergency, knyaz raised a militia comprising volunteers from the peasantry, and the druzhina served as the core of the troops. Each local knyaz served as the military leader of his troops. Such arrangements had no need for permanent ranks or positions; they were created "ad hoc", based on the task(s) in hand.