Alexander was born in Barony, Glasgow and was a shoemaker by trade. He enlisted into the Regiment on the 16th April 1834 and was appointed Corporal on the 1st May 1842. He served with the 45th in the Kaffir Wars of 1846-1859 in Natal South Africa. He became a Gaoler at Pietermaritzburg for a short time. He was discharged whilst in Natal South Africa and settled there. On the 28th March 1855, a medical report states that Alexander was suffering from the chronic disease of the liver and general decay of this health, the cause being due to the result of length of service and exposure on duty and not caused by vice or intemperance.