Baron Trevor is a British peerage title. It was created first in 1662 in the Peerage of Ireland along with the Viscountcy of Dungannon; both titles became extinct in 1706. The title was next created in the Peerage of Great Britain in 1712; the fourth Baron was created Viscount Hampden in 1776. Both titles became extinct in 1824. The final creation of the title was in the Peerage of the United Kingdom; this barony is still extant.
The title was next created in the Peerage of Great Britain in 1712 for the lawyer Sir Thomas Trevor; the fourth Baron was created Viscount Hampden in 1776.
In 1890 he was raised to the peerage as BaronTrevor, of Brynkinalt in the County of Denbigh.
BaronTrevor is in distant remainder to the Marquisate.
His second son, Thomas, BaronTrevor (1658-1730), was knighted in 1692 as solicitor-general and in 1695 became attorneygenen.
Three of his sons succeeded in turn to his barony, and a fourth son, Richard Trevor (1707-1771), was bishop of St Davids from 1744 to 1752, and then bishop of Durham.
Robert, 4th BaronTrevor and 1st Viscount Hampden (1706-1783), represented his country at the Hague from 1739 to 1746, during which time he maintained a regular correspondence with Horace Walpole.