Thomas Cook Group plc was a global travel group, headquartered in the United Kingdom and listed on the London Stock Exchange from its formation on 19 June 2007 by the merger of Thomas Cook AG — successor to Thomas Cook & Son — and MyTravel Group until 23 September 2019, when it went into compulsory liquidation. The group operated as a tour operator and airline, and also operated travel agencies in Europe. At the time of the group's collapse, approximately 21,000 worldwide employees were left without jobs (including 9,000 UK staff) and 600,000 customers (150,000 from the UK) were left abroad, triggering the UK's largest peacetime repatriation.