The 1st Division is an active division of the British Army that has been formed and disestablished numerous times between 1809 and the present. In its original incarnation as the 1st Division, it took part in the Peninsular War—part of the Coalition Wars of the Napoleonic Wars—and was disbanded in 1814 but was re-formed the following year for service in the War of the Seventh Coalition and fought at the Battle of Waterloo. It remained active as part of the British occupation of France until it was disbanded in 1818, when the British military withdrew. The division was then raised as needed; it served in the Crimean War, the Anglo-Zulu War, and the Second Boer War. In 1902, the British Army formed several permanent divisions, which included the 1st Division, which fought in the First World War, made various deployments during the interwar period, and took part in the Second World War when it was known as the 1st Infantry Division.

The 5th Infantry Division was a regular army infantry division of the British Army. It was established by Arthur Wellesley, 1st Duke of Wellington for service in the Peninsular War, as part of the Anglo-Portuguese Army, and was active for most of the period since, including the First World War and the Second World War and was disbanded soon after. The division was reformed in 1995 as an administrative division covering Wales and the English regions of West Midlands, East Midlands and East. Its headquarters were in Shrewsbury. It was disbanded on 1 April 2012.