Nickname(s) Type Leader(s) Equipment Size el>Headquarters Historical Information Established Fragmented Reformed Dissolved Notable Conflicts Affiliation [Source] The 4th was a royal infantry division that served under the British Army during World War II. Originally formed in 1809 for service during the Napoleonic Wars, it continued to serve in the British Army until it was disbanded in 2012. By the Second World War, it had consisted of men mainly from the British Expeditionary Force.