Born in Bath, Somerset, England, Marden attended Berkhamsted School and the Royal Military College at Sandhurst, from where he was commissioned as a subaltern, with the rank of lieutenant, into the Cheshire Regiment on 25 August 1886.

Leaving London in February 1900, he was senior officer in command of reinforcements on board the SS Cheshire for the journey,[5] and arrived in South Africa the following month.

[6] At the outbreak of World War I, Marden's battalion was stationed in India; it was brought back to the United Kingdom and allocated to the 84th Brigade of the 28th Division, which was to be sent to the Mediterranean.

[6] Later in November 1915, he was promoted to the temporary rank of brigadier general[12] in order to take command of the 114th Infantry Brigade, part of the 38th (Welsh) Division, a Kitchener's Army formation.

[17] During the Chanak Crisis of 1922 he played a key role in negotiating a peaceful settlement between British and Turkish forces, for which he later received a knighthood.