Complex sentence: He never married; his younger brother Henry Allan Rolls, who was heir presumptive, had died four months previously, and his youngest brother, Charles Rolls of Rolls Royce fame, had died 6 years earlier; thus the title became extinct.
Split into simpler sentences: He never married-his younger brother Henry Allan Rolls, who was heir presumptive, had died four months previously. His youngest brother, Charles Rolls of Rolls Royce fame had died 6 years earlier, thus the title became extinct.