Colonel Alexander Saunderson (1783–1857) ^[1] was a Whig MP for Cavan 1826–1831. He was a landed gentleman with 12,000 acres. Although from the Protestant planter tradition, he supported Catholic Emancipation.^[2]

Alexander Saunderson was a keen racing yachtsman on Lough Erne and a founder member c. 1818 of the group that became Lough Erne Yacht Club. He designed and built fast sailing boats at Castle Saunderson – as did his son and successor Edward. One of his most successful boats he called Bluestocking. His mother and aunt were Bluestockings. He may also have been a member of the Royal Dublin Society.^[3]

Alexander was born to Francis Saunderson and Anne Bassett White.

The Irish Saundersons were a 17th-century branch of an old family, originally of Durham; a Lincolnshire branch, the Saundersons of Saxby, held the titles of Viscount Castleton (Irish: c. 1628) and Baron Saunderson (British: c. 1714) up to 1723.

On 18 March 1828, Saunderson married Sarah Juliana, sister of fellow Cavan MP, Henry Maxwell and daughter of the Henry Maxwell, 6th Baron Farnham.^[4] They had three sons and two daughters. Their son Edward James Saunderson was also MP for Cavan 1865–1874 and later became MP for North Armagh 1885–1906.

In 1947, Saunderson's great-grandson, also named Alexander, married Louise Astor Van Alen, granddaughter of James John Van Alen and grandniece of RMS Titanic victim John Jacob Astor IV, and the ex-wife of two different Georgian Mdivani princes.^[5]