Complex sentence: While Earl of Pembroke title went to the younger, legitimate half-brother William, Jr., Richard was successful as a Gentleman Usher to Henry VII. Further, on 22 July 1509 was appointed Constable and Porter of Abergavenny Castle.
Split into simpler sentences: While Earl of Pembroke title went to his younger, legitimate half-brother William, Jr., Richard realized success through his own merit. He was successful as a Gentleman Usher to Henry VII and on 22 July 1509 was appointed Constable and Porter of Abergavenny Castle.