 Tennant was born in Belfast, Ireland, and was 29 years old when he was sentenced to transportation to Australia for life in 1823.He arrived in Sydney on 12 July 1824 on the 'Prince Regent'.He was assigned to Joshua John Moore and sent with two other men, James Clarke and John McLaughlin, to establish Moore's property "Canberry" or "Canberra", the first European habitation on the Limestone Plains.