Your Highness; His Highness; Her Highness
殿下は式典に列席された。
His Highness attended the ceremony.
大使は殿下に謁見する機会を賜った。
The ambassador was granted an audience with His Highness.
殿下の御臨席をいただき、式典は滞りなく進んだ。
With His Highness in attendance, the ceremony proceeded without a hitch.