The Golden Horde is a Russian name for the Islamic khanate that existed from the 1240s to 1502 in Russia and Eastern Europe (present-day Ukraine, Moldova, Kazakhstan, and the Caucasus). The Golden Horde was founded in the 1240s by Batu, the eldest son of Genghis Khan, one of the greatest conquerors of land in history. Genghis and his grandson Batu were Mongols, from present-day Mongolia. In a few decades, Genghis, his sons, and two grandsons had conquered most of Asia.
The Golden Horde was made out of Mongolians and numerous Turkic peoples that Batu had enlisted after conquering them. In 1235, Batu and the great general Subedei invaded westward from the Asian central steppes region, conquering the Bashkirs (in the southern Urals) and Volga Bulgaria in 1236. In 1237, he conquered Ukraine, thus moved north to begin the historic Mongol invasion of Rus, an invasion which would shape the region culturally and socially for centuries to come. After victory, he spent three years subjugating the local Russians, then moved west to destroy the armies of Hungary and Poland. This is considered one of the greatest military victories of all time, and it marked the furthest western extent of Mongol expansion. Soon after victory, Batu had to return east to handle a succession crisis caused by the death of his uncle, the Great Khan Ogedei.
Though Batu eventually died, his plans to conquer Europe never coming to fruition, the Golden Horde continued subjugating Russia, Ukraine, Moldova, and Kazakhstan for centuries. The Golden Horde were early-adopters of Islam, the majority being Turkic people, with the leaders being the descendants of Batu's original Mongol warriors. These people came to be known as Tartars by the native Russians, and many Russians today have Tartar blood in them.
The capital of the Golden Horde's empire, Sarai Berqe, became one of the largest cities in the medieval world, with over 600,000 inhabitants. Due to low levels of literacy, much of the activity in this time and area is poorly documented. In the 1340s, the empire began to slowly fall apart, succumbing to extensive infighting and massive casualties due to the Black Death, which was sweeping Eurasia at the time. In 1480, the Muscovite Russians finally broke free of the Horde's control, annexing their territories and setting the stage for the Russia of today, dominated by ethnic Russians.