Alexander Campbell Sinclair, 13th Earl of Caithness (1790-1855) (1790–1855) Parents James Sinclair, 12th Earl of Caithness Jean Campbell Children William Leigh Canning Sinclair James Sinclair, 14th Earl of Caithness Alexander Eric George Sinclair Siblings Lady Charlotte Sinclair Lady Janet Sinclair John Sinclair, Lord Berriedale Eric George Sinclair John Sinclair James Sinclair Patrick Campbell Sinclair Partners Frances Harriet Leigh