Baron Waltham, of Philipstown, 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 in 1762 for John Olmius, previously Member of Parliament

Member of Parliament

A Member of Parliament is a representative of the voters to a :parliament. In many countries with bicameral parliaments, the term applies specifically to members of the lower house, as upper houses often have a different title, such as senate, and thus also have different titles for its members,...

 for Weymouth and Melcombe Regis

Weymouth and Melcombe Regis (UK Parliament constituency)

Weymouth and Melcombe Regis was a parliamentary borough in Dorset represented in the English House of Commons, later in that of Great Britain, and finally in the Parliament of the United Kingdom. It was formed by an Act of Parliament of 1570 which amalgamated the existing boroughs of Weymouth and...

. His son, the second Baron, represented Maldon

Maldon (UK Parliament constituency)

Maldon is a county constituency represented in the House of Commons of the Parliament of the United Kingdom. It elects one Member of Parliament by the first past the post system of election...

 in the House of Commons

British House of Commons

The House of Commons is the lower house of the Parliament of the United Kingdom, which also comprises the Sovereign and the House of Lords . Both Commons and Lords meet in the Palace of Westminster. The Commons is a democratically elected body, consisting of 650 members , who are known as Members...

. However, he was childless and on his death in 1787 the barony became extinct. The Honourable Elizabeth Olmius, only daughter of the first Baron, married John Luttrell, later third Earl of Carhampton. In 1787 he assumed by Royal licence the additional surname of Olmius as a mark of respect for his father-in-law. However, the earldom and its subsidiary titles became extinct on his death in 1829.

Barons Waltham (1762)

• John Olmius, 1st Baron Waltham (1711–1762)
• Drigue Billers Olmius, 2nd Baron Waltham
  Drigue Olmius, 2nd Baron Waltham
  Drigue Billers Olmius, 2nd Baron Waltham , was a British politician.Olmius was the son of John Olmius, 1st Baron Waltham, by Anne, daughter of Sir William Billers, Lord Mayor of London in 1733. He succeeded his father in the barony in October 1762, aged 16...
  
  (1746–1787)