What is "mukhsha"

Mukhsha or Muxşa (Naruçat) was a medieval city in 14th-15th centuries in Golden Horde. It was a center of Mukhsha Ulus. In 1313-1367 the city minted its own coins. In the 15th century the city lost its importance and declined. The ruins (bricked building, bath, Muslim graves) are situated in Penza Oblast near the modern town of Narovchat in the upper stream of Moksha River.