The oldest settlement in the territory of Ustyluh existed back in the
Copper Age. During the times of
Kievan Rus (9th to 12th centuries CE), there was a fortified settlement in the same location, with a necropolis nearby consisting of 29 burial mounds. In 1897, archaeologist M. F. Bilyashevsky excavated three of these mounds. Ustyluh was among the fortified towns taken by
Volodymyr the Great. To this day, a pentagonal fortress remains, surrounded by earthen ramparts made of beaten clay, which in height are not inferior to the ramparts of Volodymyr's capital, and it is pierced from the east by the city gate. Until the
Russian Revolution of 1917, it was a settlement in
Vladimir-Volynsky Uyezd of
Volhynian Governorate of the
Russian Empire; from 1921 to 1939 it was part of
Wołyń Voivodeship of
Poland, within which it had
miasteczko (small town) status. According to the 1921 census, the population was 67.1%
Jewish, 23.3%
Polish, and 9.6%
Ukrainian. Following the German-Soviet
invasion of Poland, which started
World War II in September 1939, Uściług was occupied by the
Soviet Union until 1941. It has been a town since 1940. In January 1989 the population was 2,404 people. With the opening of the Ustyluh-
Zosin international border crossing, the city's role has grown especially important. After Ukraine gained its independence, the Ustyluh-Zosin international border crossing with Poland was opened in the city. In August 2015, the city became the center of the newly created Ustyluh urban hromada. ==Demographics==