G4S plc (formerly Group 4 Securicor) is a British multinational security services company headquartered in Crawley, West Sussex. It is the world's largest security company measured by revenues and has operations in around 125 countries. With over 620,000 employees, it is one of the world's largest private sector employers. G4S was founded in 2004 by the merger of the UK-based Securicor plc with the Denmark-based Group 4 Falck.
G4S has its origins in a guarding business founded in Copenhagen in 1901 by Marius Hogrefe, originally known as Kjøbenhavn Frederiksberg Nattevagt (which translates asCopenhagen and Frederiksberg Night Watch) and subsequently renamed Falck.In 2000 Group 4, a security firm formed in the 1960s, merged with Falck to form Group 4 Falck. In 2002 Group 4 Falck went on to buy The Wackenhut Corporation in the USA.
2004 to 2010
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 London and Copenhagen Stock Exchanges. In 2005, Lars Nørby Johansen was succeeded as Chief Executive by Nick Buckles and, in 2006, the new G4S brand identity 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.