Ulugh Muhammad from the heartland of the Golden Horde in 1438, being proclaimed Khan in Sarai. Throughout the rules of Küchük Muhammad and Sayid Ahmad I, the Tatars tried to force their Russian subjects to pay taxes, invading them in 1449, 1450, 1451 and 1452. These attacks led to retaliation from the Polish-Lithuanian Commonwealth, who allied with the Crimean Khanate. At the same time, envoys from Lithuanian nobles who were unhappy being under a Polish-dominant Commonwealth brought gifts to Sayid Ahmad, who invaded Poland-Lithuania in 1453. In 1455, the Crimeans again attacked Sarai, forcing Sayid Ahmad to flee to Kiev. However, a force led by Andrzej Odrowąż marched upon Kiev and captured him, leading him to die in prison. Further raids include a Tatar raid on Podolia in 1457 (ending in victory for the Tatars) and one in 1459 on Muscovy (ending in a victory for the Muscovites) Descendants of Küchük Muhammad Küchük Muhammad was succeeded by his son Mahmud bin Küchük in 1459. Mahmud was usurped by his brother Ahmed Khan bin Küchük in 1465. Mahmud headed to Astrakhan, seceding and forming the Astrakhan Khanate. This led to the creation of a rivalry between the two Khanates, ending with Ahmed's descendants occupying the throne of Astrakhan in 1502. In 1469, Ahmed attacked and killed the Uzbek Abu'l-Khayr Khan. In the summer of 1470, Ahmed organized an attack against Moldavia, the Kingdom of Poland, and Lithuania. By August 20, the Moldavian forces under Stephen the Great defeated the Tatars at the battle of Lipnic. By the 1470s, Muscovy had stopped paying tribute to Sarai, but continued to maintain diplomatic relations with them. In 1474 and 1476, Ahmed insisted that Ivan III of Russia recognize the khan as his overlord. In 1480, Ahmed organized a military campaign against Moscow, resulting in a face off between two opposing armies known as the Great Stand on the Ugra River. Ahmed judged the conditions unfavorable and retreated. This incident formally ended the "Tatar Yoke" over Rus' lands. On 6 January 1481, Ahmed was killed by Ibak Khan, the prince of the Khanate of Sibir, and Nogays at the mouth of the Donets River. The Crimean Khanate, which had become a vassal state of the Ottoman Empire in 1475, subjugated what remained of the Great Horde, sacking Sarai in 1502. After seeking refuge in Lithuania, Sheikh Ahmed, last Khan of the Horde, died in prison