Noble families of Don Cossacks in alphabetical order includes the old original Cossack noble families from Free Don, families which titles were granted by the Tsars of Moskovia and Russian Imperators after including of the territories of Free Don in to Russian Imperium. Most of the origin Don Cossacks families were a landowners that provoked Russian peasants to escape to Don and work on their lands, like General Atamans of the Efremov family. Free territories of Don Cossacks known from the beginning of 14th century until the end of the 16th century when Moscow gained control of them.