| Jakiv Ostranin | |
| Death Date: | 1641 |
| Known For: | Ostryanyn uprising |
| Partner: | Małgorzata from Bnina Łódz coat of arms |
| Children: | Iskra Ivan Yakovych |
Yakov Stepanovich Iskra of the Kopacz coat of arms,[1] also known as Ostrzanin or Ostranica (uk. Яків Остряниця, d. 6 May 1641), was a Cossack hetman and leader of the Ostryanyn uprising. He was descended from the noble family of Iskra of Ostera.
The first references to him relate to his participation in the Polish-Russian war in 1633, where he served as a colonel of the Registered Cossacks.[2] In 1638 he was elected hetman of the non-registered Cossacks and in the same year initiated an uprising against the Polish-Lithuanian Commowealth. After losing the Battle of Zhovnyn, he fled to the Russian Empire, where he settled.[3] In Chuguev, the settlers under the command of Ostryanin participated in the fight against the Tatars, who were raiding the southern borders of the Russian state.[4] Yakov died on 6 May 1641, killed by Cossacks during a riot caused by conflicts between privates and Cossacks starshyna.[5]