G4S is a British multinational private security company headquartered in London, England. The company was set up in 2004 when London-based Securicor amalgamated with Danish firm Group 4 Falck. The company offers a range of services, including the supply of security personnel, monitoring equipment, response units and secure prisoner transportation. G4S also works with governments overseas to deliver security services.
G4S is the world's largest security company measured by revenues. It has operations in more than 85 countries. With over 533,000 employees, by 2012 it was the largest European and African private employer.
The company has been criticized and involved in numerous controversies. Formerly a dual-listed company with listings on the Copenhagen and London stock exchanges, G4S was purchased by Allied Universal in April 2021.
G4S has its origins in a guarding business founded in Copenhagen in 1901 by Marius Hogrefe, originally known as København Frederiksberg Nattevagt and subsequently renamed Falck.
In 2000, Group 4, a security firm formed in the 1960s, merged with Falck to form Group 4 Falck and by 2000 the company was described as "the world's largest private security systems company". In 2002 Group 4 Falck went on to buy The Wackenhut Corporation in the United States.
G4S was formed in July 2004, when Group 4 Falck's security business merged with Securicor to create Group 4 Securicor and began trading on both the Copenhagen and London Stock Exchanges. In 2005, Lars Nørby Johansen was succeeded as chief executive by Nick Buckles and, in 2006, the new G4S brand identity, designed by Russell Johnson of UK design agency Stylus, was rolled out across its business worldwide. In the same year, Alf Duch-Pedersen succeeded Jorgen Philip-Sorensen to become the non-executive chairman of the business.