He had previously served as a Captain in the 23rd Foot Regiment, but transferred to the 7th Light Dragoons on 15 June 1809. He served in the peninsula from August 1813 to April 1814, so it would appear that he wrote in two sequential journals, but we now only have the second covering the last few months of the war. From December 1813 Keane served on the staff of Lieutenant Colonel Vivian.
From the first storm to the capture of the castle in 1813, by Lieutenant-Colonel Harvey Jones, H.E.
The Peninsular War Diary of Lieutenant John Alexander Wilson, 2nd Foot
An unknown soldier of the 38th (1st Staffordshire) Regiment, he states that he was in hospital at Salamanca in 1812 and made a prisoner of war until the end of the war in 1814 and then took the opportunity to take his discharge from the army soon after.