LeBrun was a Manticoran peerage.
In the mid-18th Century PD (more specifically, starting in 1857), Sir Orwell LeBrun was a member of Parliament and the leader of the Liberal Party. He believed that the claims of the aggressive expansionism of the People's Republic of Haven were exaggerated, and was against both the buildup of the Royal Manticoran Navy instigated by King Roger and the annexation of the Basilisk System with it's associated terminus. LeBrun was instrumental in preventing the full annexation of the planet of Medusa to Manticoran control. (Companion)
The holder of the title in 1883 PD was the leader of the Crown Loyalists during the later reign of King Roger III. Queen Elizabeth III named him as regent for Maralise Kemeny when her father was forced to renounce his seat in the House of Lords in her favor. (HHA2.3: QG)