The Tula Principality was a historical region in Russia, located around the city of Tula. It emerged during the medieval period and played a significant role in the development of the surrounding areas. The principality was known for its strategic location, which facilitated trade and military activities. During its existence, the Tula Principality was often involved in conflicts with neighboring states, including the Mongol Empire and other Russian principalities. It eventually became part of the Grand Duchy of Moscow in the late 15th century, contributing to the unification of Russia under Moscow's rule.