Bristow Helicopters was established by Alan Bristow in June 1955; two years later, it acquired its first pair of helicopters in the form of the Westland Widgeon. The company quickly expanded overseas as well as various services, including helicopter training, oil exploration, search and rescue, and charter flights. Having entered the African market in 1960, Nigeria became Bristow's biggest profit centre during the 1970s. Entering the North Sea market, also during the 1960s, Bristow became Aberdeen Airport's largest single employer during the 1980s and was operating the majority of offshore flights in the North Sea. The company went through repeated changes in ownership during the 1980s and 1990s, leading to its acquisition by American helicopter operator Offshore Logistics in 1996, which re-branded itself as "The Bristow Group" in February 2006.