The house flag of Dorey Onesimus & Sons Ltd, Guernsey. A red ractangular flag bearing a white diamond with the blue letter 'D' in the centre. A rope and toggle is attached.

Onesimus Dorey and Sons began as a company called Plymouth, Channel Islands and Brittany Steamship Company, founded by Onesimus Dorey in the 1887. The company’s first steamer was the ‘Commerce’, which was followed by the ‘Channel Queen’. Both of these ships ran regular schedules between Plymouth and two Brittany ports, via Guernsey and Jersey. In 1898 the ‘Channel Queen’ was wrecked. The company was forced to sell the remaining ship, however quickly a new company was formed with the ship the ‘Rossgull’. The company’s bad luck continued when this ship was also wrecked. Dorey began to use chartered ships until the Guernsey Commercial Bank helped the company purchase the ‘Devonia’. The company’s ships were used for the war effort during World War I, and in 1921 the company suffered greatly during the depression that followed and had to end all services. Dorey managed to stay in business, however, and managed a company which brought coal to the Channel Islands from Swansea and the north-east English coast (Onesimus Dorey Ltd Tramp Steamers).

In 1940, the company moved its entire fleet of five steamers to London. Three of these sunk during the war, but the other two continued to operate after 1945. In 1963, Onesimus Dorey’s grandson, Peter Dorey, purchased two-thirds share in the Condor Ferry Company, which is still in business today. Peter Dorey was drowned during the 1979 Fastnet Race and Condor was sold to Normans of Commodore Shipping.