Armies of the Rus' principalities

[2] However, these squads, as a rule, did not exceed the number of several hundred men, and were unsuitable for united actions under a single command.

While militia infantry still existed, they were, from XIV onward, mostly armed with ranged weapons, and delegated auxiliary duties, such as defending cities.

Under Tatar influence, the mail and lamellar armour of Kievan Rus' was replaced with brigandine ("Kuyak"), mail and plate ("Behterets") and mirror armour("Zertsalo"),[9] while poor noblemen and armed serfs wore long aketons ("Tyegilyai").

[citation needed] In the 15th century, the Grand Duchy of Moscow gradually conquered and annexed the northeastern Rus' principalities.

This process is associated with reforming the Muscovite army, as new princedoms were absorbed, courts of independent princes were dismissed, and "service people" passed to the grand duke.

As a result, the vassal princes and boyars were transformed into state servants, who received estates for service in conditional holding (less often - in fiefdom).

Thus, the "Landed Army" (Russian: Поместное войско) was formed, the bulk of which were noblemen and "boyar's children", with their armed slaves.