Original: He was made Cardinal-Bishop of Frascati on 13 July 1761, and eventually succeeded to the See of Ostia and Velletri on his appointment as Dean of the Sacred College of Cardinals on 26 September 1803.
Simplified: He was made Cardinal Priest in 1748, and Cardinal-Bishop of Frascati on 13 July 1761. When he became the senior cardinal Dean of the Sacred College of Cardinals on 26 September 1803, he transferred to the See of Ostia and Velletri.