TUI Group is a German leisure, travel and tourism company; it is the largest such company in the world. TUI is an acronym for Touristik Union International. TUI AG was known as Preussag AG until 1997 when the company changed its activities from mining to tourism. It is headquartered in Hanover, Germany.

Thomas Cook & Son, originally simply Thomas Cook, was a company founded by Thomas Cook, a cabinet-maker, in 1841 to carry temperance supporters by railway between the cities of Leicester, Nottingham, Derby and Birmingham. In 1851, Cook arranged transport to the Great Exhibition of 1851. He organised his first tours to Europe in 1855 and to the United States in 1866.