Iaşi (yäsh) [key] or Jassy yäˈsē, city (1990 pop. 346,577), E Romania, in Moldavia, near the Republic of Moldova. Iaşi is the administrative and commercial center of a fertile agricultural region. Chemicals, pharmaceuticals, plastics, and textiles are produced. In 1565, Iaşi succeeded Suceava as the capital of the Romanian principality of Moldavia, a position it held until Moldavia and Walachia were united in 1859. The city was repeatedly burned and sacked by Tatars, Turks, and Russians. A treaty signed there in 1792 ended the second of the Russo-Turkish Wars of Catherine II. In Iaşi, long an important cultural center, the first book in the Romanian language was printed (1643) and the national theater was founded (1849). During World War I the city served as Romania's temporary capital while German forces occupied Walachia. Iaşi's large Jewish population was massacred by the Nazis in one of the worst pogroms in history. Soviet troops took the city in 1944. Iaşi is the see of an Orthodox archbishop and has a university (founded 1860) and other institutions of higher education. Landmarks include the 17th-century cathedral, the Church of the Three Hierarchs (17th cent.), and the Church of St. Nicholas (15th cent.), all outstanding examples of the Moldavian adaptation of Byzantine architecture.