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In page Murad II:

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In 1448 he defeated the Christian coalition at the Second Battle of Kosovo (the first one took place in 1389).[3] When the Balkan front was secured, Murad II turned east to defeat Timur's son, Shah Rokh, and the emirates of Karamanid and Çorum-Amasya.[citation needed] In 1450 Murad II led his army into Albania and unsuccessfully besieged the Castle of Krujë in an effort to defeat the resistance led by Skanderbeg. In the winter of 1450–1451, Murad II fell ill, and died in Edirne. He was succeeded by his son Mehmed II (1451–1481).