At the request [insistence?] of Yvonne's father when Bruce married Yvonne he adopted her surname in place of his then surname, Harris. Bruce agreed to this because Yvonne was ‘the last of her line’ which presumably her father hoped to perpetuate by this stratagem. Vanitas vanitatum etc. The father failed in this objective as Bruce and Yvonne had no children and after Yvonne's death Bruce used his middle name, Clifton, as his surname.