The costume of the sitter in the present portrait places the picture around the 1820s. The hon. admiral Sir Henry Blackwood (1770-1832) was in his forties by the 1820s, and therefore the sitter in the present portrait is more likely to be his son, Sir Henry-Martin Blackwood (1801-1851). Sir Henry-Martin was a captain in the navy, and married Harriet-Louisa, daughter of J.M. Bulkeley, in 1826, aged twenty-five.