Earl of Airth

Owing to the uncanonicity of the marriage of Robert II to Elizabeth Mure, and the 1373 Act which only sidestepped this question for heirs male of Robert II's sons, William Graham's ancestors potentially had a better claim to the Scottish throne than Mary, Queen of Scots.

In 1834 Capt Robert Barclay Allardice of Ury and Allardice petitioned the King to be recognised as Earl of Airth as a descendant of William Graham, 1st Earl of Airth, his great-great-great-grandfather, basing his claim on the fact that the Letters Patent of 1633 specified descent to 'heirs general', rather than limiting it to 'heirs male'.

No decision was forthcoming and in 1840 Capt Barclay Allardice petitioned Queen Victoria for him to be recognised as Earl of Strathearn, Menteith and Airth.

The Committee for Privileges heard evidence in support of the opposing claims in 1870 and 1871, but came to no decision, and the three Earldoms remained dormant.

On 29 April 2011, Queen Elizabeth II conferred the title of Earl of Strathearn on Prince William of Wales.