Complex sentence: George Nugent-Temple-Grenville, undertook the grand tour in 1774, in 1775 he married a Catholic heiress Mary Nugent, who had an income of £14,000 a year.
Split into simpler sentences: George Nugent-Temple-Grenville undertook the grand tour in 1774. In 1775 he married a Catholic heiress Mary Nugent, who had an income of £14,000 a year.