Complex sentence: O'Brien was the son of Edward O'Brien, the second Baronet of Leaghmenagh and Mary Hickman, inheriting the Baronetcy on the death of his father in 1765.
Split into simpler sentences: O'Brien was the son of Edward O'Brien, the second Baronet of Leaghmenagh and Mary Hickman. O'Brien inherited the Baronetcy on the death of his father in 1765.