The First World War (1914–1918) produced casualties on a previously unseen scale. Over 1.1 million men from the British Empire were killed. In its aftermath, thousands of war memorials were built across Britain, the Empire, and the former battlefields. Amongst the most prominent designers of war memorials was Sir Edwin Lutyens, described by Historic England as "the foremost architect of his day". Lutyens established his reputation designing country houses for wealthy clients around the turn of the 20th century and became a public figure as the designer of much of New Delhi, the new capital of British India. The war had a profound effect on Lutyens and following it he devoted much of his time to the commemoration of casualties. By the time he was commissioned for the cenotaph, he was already acting as an adviser to the Imperial War Graves Commission.
Lutyens' first war memorial was the Rand Regiments Memorial in Johannesburg, South Africa, dedicated to casualties of the Second Boer War (1899–1902). His first commission for a memorial to the First World War came from Southampton. The word "cenotaph" derives from the Greek term "kenotaphion". Lutyens first encountered the word in connection with Munstead Wood, the house he designed for Gertrude Jekyll in the 1890s. There he designed a garden seat in the form of a rectangular block of elm set on stone, which Charles Liddell—a friend of Lutyens and Jekyll and a librarian at the British Museum—christened the "Cenotaph of Sigismunda". Lutyens remembered the term when working on Southampton's memorial in early 1919, where he proposed a cenotaph after his first design was rejected on cost grounds. The end result (unveiled a week before the permanent version of the Whitehall cenotaph) lacks the subtlety of Whitehall's monument, but introduces several design elements common in Lutyens' subsequent memorials, including Whitehall.