Wilton was born in Samalkota, India, in 1862, the second son of Dr Jacob Wilkins (1830–1879) and Judith Laura née Montefiore (1835–1899). He received his early education at Brighton and Southsea Military College, where he graduated in 1880. He joined the militia the following year, attending Royal Military Academy Sandhurst, obtaining his commission in 1883 as a Lieutenant in the Connaught Rangers. He saw active service in the Burma Campaigns of 1885, 1887 and 1889 and was awarded a medal and two clasps.