Kreva (Belarusian: Крэва, IPA: [ˈkrɛva]; Russian: Крево, romanized: Krevo; Lithuanian: Krėva, Krẽvas; Polish: Krewo) is an agrotown in Smarhon District, Grodno Region, Belarus. It serves as the administrative center of Krevas selsoviet.
The first mention dates to the 13th century. The toponym is derived from the name of the Krivichs tribe.
In a strict sense, the Union of Krewo or Act of Krėva (also spelled Union of Krevo, Act of Kreva; Polish: unia w Krewie; Lithuanian: Krėvos sutartis) comprised a set of prenuptial promises made at Kreva Castle on 14 August 1385 by Jogaila, Grand Duke of Lithuania, in regard to his prospective marriage to the underage reigning Queen Jadwiga of Poland.
Though very limited in scope, the "Union of Krewo", in historiography, often refers not only to the particular document but to events of 1385–1386 as a whole. After the 1385 negotiations, Jogaila converted to Christianity, married Jadwiga, and was crowned King of Poland in 1386.
Kreva Castle (Belarusian: Крэўскі замак, Lithuanian: Krėvos pilis, Polish: zamek w Krewie) is the ruins of a major fortified residence of the rulers of Grand Duchy of Lithuania Gediminas and Algirdas in the village of Kreva, Belarus. The village lies 220 metres (720 ft) above sea level.
During the Lithuanian Civil War (1381–1384), Jogaila, Algirdas's son, arrested and imprisoned his uncle Kęstutis and cousin Vytautas in the Kreva Castle in 1382. One week later, Kęstutis was found dead. Whether he died of natural causes or was murdered is still a matter of debate. His son, Vytautas, however, escaped from Kreva and fled to the Teutonic Order.