It was divided between the County of
Montefeltro (later
Duchy of Urbino) and the
Sovereign County of Carpegna and in 1685 became the seat of an independent Principality of the
Carpegna family with the title of
Prince of the Holy Roman Empire, the first Prince Ulderico was a grandson of
Robert Dudley, titular
Duke of Northumberland. Until 15 August 2009, the comune belonged to the
Marche (
Province of Pesaro-Urbino) from which it was detached, together with six other municipalities of the Alta Valmarecchia area, following the implementation of the outcome of a referendum held on 17 and 18 December 2006. Pennabilli is still the seat of the
Diocese of San Marino-Montefeltro. ==References==