It was created in 1836 for Dominick Browne, who had earlier represented County Mayo in the House of Commons.
His son, the second Baron, sat in the House of Lords as an Irish representative peer from 1869 to 1900.
He was an Irish Representative Peer from 1902 to 1926 and a member of the short-lived Senate of Southern Ireland.
Lord Oranmore and Browne died in August 2002, aged 100 years and 291 days.
The case – Baron Mereworth v Ministry of Justice – was dismissed on the grounds that the High Court did not have jurisdiction on how the House of Lords conducted its business.