As with other nearby settlements, the place name (originally
Grouts) is of Slavic origin and means
gord. The first documented mention of the settlement dates from 1209. The prime location of Greiz on the confluence of the
White Elster river and its tributary Göltzsch helped to make it a fast-growing town. From the 12th century it was governed by
advocati (), but in 1236 it came into the possession of
Gera. It was recognized as a town in the 13th century. Later the
House of Reuss, a ruling German dynasty whose male members were all named Heinrich, built two castles in Greiz: the "Oberes Schloss" (Upper Castle) and the "Unteres Schloss" (Lower Castle). Both were built by famous architects and are still considered unique. Greiz became the capital of the
Principality of Reuss-Greiz until 1918. The town was wholly destroyed by fire in 1494, and almost totally in 1802. During
World War II, Greiz did not suffer much damage, although 3 of the 5 bridges in town were destroyed.
Ulf Merbold, who became the first astronaut from
West Germany in 1983, was born here in 1941. Greiz has a population of about 20,400 people. The former municipality
Neumühle/Elster was merged into Greiz in December 2019. ==Economy==