The 58th (2/1st London) Division was an infantry division of the British Army, which was active in World War I.
In late August 1914 the War Office issued instructions for all formations of the Territorial Force to form reserve units. The men who had agreed to serve overseas were separated from the rest. Those left as 'home service only' were formed into 'second line' units, to create this reserve. In the London area, the 1st London Division became the first-line formation, while the second-line formation was given the designation 2/1st London Division. When many of the 'first line' units of the senior 56th (1st London) Division were sent overseas, that Division was temporarily disbanded and the rest of its units joined the 'second line' in the 2/1st London Division. In August 1915, the number 58 was allocated to the 2/1st London Division.
The Division arrived in France in July 1917, and took part in many of the major battles, including The Battle of Bullecourt 1917, The Second Battle of Passchendaele 1917, The Somme 1918, and Battle of Amiens 1918.
They were to serve in France and Flanders until the Armistice, when it was disbanded.
During WW2 the 58th Division was recreated, as an imaginary 'deception' formation. The division was 'reformed' as a 'phantom division' created as part of 'Operation Fortitude North' as a replacement for the British 3rd Infantry Division which was going south to take part in a D-Day rehearsal. Unlike other 'phantom divisions' the 58ths number was chosen on the basis of Ultra reports that showed the Germans believed a 58th Infantry Division existed in the vicinity of Windsor.