A Day in History The Battle of Cape Medhab near the city of Iskar, the capital of the Siberian Khanate, on November 5, 1582, on Cape Medhab, a battle took place between a detachment of Cossacks led by Armak and the Siberian Tatars led by Khan Kuchum. The battle ended in the victory of Armak's expedition and largely led to the fall of the Siberian Khanate.