Longueval is a village 40 kilometres north-east of Amiens and 12 kilometres east-north-east of Albert, a town on the D929 road from Amiens to Bapaume and Cambrai. From the D929 direction Bapaume-Albert take the 2nd turning for Martinpuich and continue along the D6 direction Longueval, for 2 kilometres. London Cemetery and Extension will be found on the right hand side of the road.

High Wood was fiercely fought over during the Battle of the Somme until cleared by 47th (London) Division on 15 September 1916. It was lost during the German advance of April 1918, but retaken the following August. The original London Cemetery at High Wood was begun when 47 men of the 47th Division were buried in a large shell hole on 18 and 21 September 1916. Other burials were added later, mainly of officers and men of the 47th Division who died on 15 September 1916, and at the Armistice the cemetery contained 101 graves. The cemetery was then greatly enlarged when remains were brought in from the surrounding battlefields, but the original battlefield cemetery is preserved intact within the larger cemetery, now know as the London Cemetery and Extension. The cemetery, one of five in the immediate vicinity of Longueval which together contain more than 15,000 graves, is the third largest cemetery on the Somme with 3,873 First World War burials, 3,114 of them unidentified.

London Cemetery and Extension was used again in 1946 by the Army Graves Service for the reburial of Second World War casualties recovered from various temporary burial grounds, French military cemeteries, small communal cemeteries, churchyards and isolated graves, where permanent maintenance was not possible. These graves are in one central plot at the extreme end of the cemetery, behind the Cross of Sacrifice. Second World War burials number 165. The cemetery was designed by Sir Herbert Baker.