Baron Riversdale, of Rathcormuck in the County of Cork, was a title in the Peerage of Ireland

Peerage of Ireland

The Peerage of Ireland is the term used for those titles of nobility created by the English and later British monarchs of Ireland in their capacity as Lord or King of Ireland. The creation of such titles came to an end in the 19th century. The ranks of the Irish peerage are Duke, Marquess, Earl,...

. It was created on 13 October 1783 for William Tonson, who had earlier represented Rathcormack

Rathcormack (Parliament of Ireland constituency)

Rathcormack was a constituency represented in the Irish House of Commons from 1611 to 1800. It was a mix of Potwalloping and a Manor Borough established by Charter and remained tied to the borough and surrounding area. The franchise was vested in the £5 and until 1793, Protestant Freeholders and...

 and Tuam

Tuam (Parliament of Ireland constituency)

Tuam was a constituency represented in the Irish House of Commons to 1800.-1692–1801:...

 in the Irish House of Commons

Irish House of Commons

The Irish House of Commons was the lower house of the Parliament of Ireland, that existed from 1297 until 1800. The upper house was the House of Lords...

. His eighth son, the third Baron (who succeeded his elder brother in 1848), was Bishop of Killaloe and Clonfert

Bishop of Killaloe and Clonfert

The Bishop of Killaloe and Clonfert was the Ordinary of the Church of Ireland diocese of Killaloe and Clonfert; comprising all of County Clare and part of counties of Tipperary, Galway and Roscommon, Ireland.-History:Under the Church Temporalities Act 1833, the Episcopal see was a union of the...

. The title became extinct on his death in 1861. The Tonson family descended from Benjamin Tonson, Treasurer of the Navy

Treasurer of the Navy

The Treasurer of the Navy was an office in the British government between the mid-16th and early 19th century. The office-holder was responsible for the financial maintenance of the Royal Navy. The office was a political appointment, and frequently was held by up-and-coming young politicians who...

 during the reign of Queen Elizabeth I

Elizabeth I of England

Elizabeth I was queen regnant of England and Ireland from 17 November 1558 until her death. Sometimes called The Virgin Queen, Gloriana, or Good Queen Bess, Elizabeth was the fifth and last monarch of the Tudor dynasty...

. His descendant Richard Tonson was granted lands in Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 for his services during the English Civil War

English Civil War

The English Civil War was a series of armed conflicts and political machinations between Parliamentarians and Royalists...

 and settled at Spanish Island

Spanish Island

Spanish Island is an island of the British Virgin Islands in the Caribbean....

, County Cork

County Cork

County Cork is a county in Ireland. It is located in the South-West Region and is also part of the province of Munster. It is named after the city of Cork . Cork County Council is the local authority for the county...

. His grandson Richard Tonson was a member of the Irish Parliament for Baltimore

Baltimore (Parliament of Ireland constituency)

Baltimore was a potwalloper constituency represented in the Irish House of Commons from 1614 to 1801.-Boundaries and Boundary Changes:This constituency was based in the town of Baltimore in County Cork.-Potwalloper:...

 for many years. The latter's only son was the aforementioned William Tonson who was elevated to the peerage in 1783.

Barons Riversdale (1783)

• William Tonson, 1st Baron Riversdale (1724–1787)
• William Tonson, 2nd Baron Riversdale (1775–1848)
• Ludlow Tonson, 3rd Baron Riversdale
  Ludlow Tonson, 3rd Baron Riversdale
  The Rt Rev. Ludlow Tonson, 3rd Baron Riversdale, DD was a Church of Ireland bishop, the 3rd holder of the office of Bishop of Killaloe, Kilfenora, Clonfert and Kilmacduagh. Born on 6 March 1784, he was consecrated on 17 February 1839 and succeeded his brother in 1848. He died on 13 December...
  
  (1784–1861)