Greenwich Island (variant historical names Sartorius Island, Berezina Island) is an island 24 km (15 mi) long and from 0.80 to 9.66 km (0.5 to 6 mi) (average 5.23 km or 3.25 mi) wide, lying between Robert Island and Livingston Island in the South Shetland Islands. Surface area 142.7 square kilometres (55.1 sq mi). The name Greenwich Island dates back to at least 1821 and is now established in international usage.