Complex sentence: Dudley Persse (1625--1699) was an Anglo-Irish landlord, a grandson of the Rev. Robert Persse, thought to have originated in Northumberland but who settled in Ireland in the late 16th century.
Split into simpler sentences: Dudley Persse (1625--1699) was an Anglo-Irish landlord. He was a grandson of the Rev. Robert Persse who is thought to have originated in Northumberland but settled in Ireland in the late 16th century.