Complex sentence: He was given command the yacht HMS "Prince Regent" in December 1828 and, having been promoted to rear-admiral on 22 July 1830, he was appointed second-in-command of the Channel Squadron, under Sir Edward Codrington, in April 1831.
Split into simpler sentences: He was given command the yacht HMS "Prince Regent" in December 1828. Promoted to rear-admiral on 22 July 1830, he was appointed second-in-command of the Channel Squadron, under Sir Edward Codrington, in April 1831.