Costello, Mary Ann (1747–1827), actress and mother of the British prime minister George Canning, was born in Ireland, daughter of Jordan Costello, a Connacht squire. Apparently orphaned at an early age, she was brought up in the care of her maternal grandfather, Col. Guydickens, in London. Penniless but renowned for her beauty, she fell in love with George Canning (qv) (1730?–1771) and they married in 1768. In the spring of 1769 their first child, a daughter, was born but died within a few months. On 11 April 1770 Mary gave birth to a son, named after his father. A year later her husband died, leaving Mary, pregnant again, without any financial support. Deciding to pursue a career on the stage, she made her debut in ‘Jane Shore’ at Drury Lane (November 1773). Not a success, she was forced to settle for more modest aspirations in provincial theatre. With Samuel Reddish, a disreputable figure, she bore five children; including two sets of twins. She may have married him – she indeed referred to herself as ‘Mrs Reddish’ – but there is no evidence of a union. Young George was taken from Mary and placed in the care of his uncle Stratford Canning, and she did not see him for eight years.
In February 1783 she remarried, this time to Richard Hunn , an unsuccessful silk mercer from Plymouth. She had a further five children by Hunn, including another set of twins. Her acting career continued to cause consternation, and at the age of 12 George was told that his mother was unfit for respectable society. All the time, George looked for ways to rescue his mother from financial need; in June 1791 he sent her 100 guineas (£105), and warned that if she continued in the theatre it would damage his future career. In the 1790s Mary's relationship with Hunn collapsed and she retired from the stage. George was beginning his political career as an MP, and myriad half-brothers descended on him for help. Mary, meanwhile, attempted to make her fortune with an eye ointment that she had invented, ‘Collysium’; when George tried it his eye became inflamed.
Kept at a respectable distance from her rising son, in 1803 she received an annual pension of £500 and was able to live the remainder of her life in relative comfort. But it was only in 1804, four years after George's marriage, that she was allowed meet her daughter-in-law and grandchildren. In the 1820s, when George was at the height of his political career, his mother's past was used regularly against him. Her career as an actress and her disreputable private life were held up as proof that her son was unsuitable for the highest office. In 1827 the whig Lord Grey declared that being the son of an actress disqualified George from the premiership. Mary Ann died 10 March 1827 at Henrietta St., Bath, a few months before her son became prime minister.