Yesaul
（重定向自Esaul）
- For the town in Armenia, see Ovuni.
Yesaul, or Osaul ( Russian:есау́л [jɪsɐˈul]), Ukrainian:осавул (from Turkic yasaul - chief), a post and a rank in the Ukrainian and Russian Cossack units.
The first records of the rank imply that it was introduced by Stefan Batory, King of Poland in 1576.