Complex sentence: He completed his education at Trinity College, Dublin, and, apparently without waiting to take a degree, entered the foreign office on 15 October 1817 as attaché to his uncle, the Earl of Clancarty, at the Hague.
Split into simpler sentences: He completed his education at Trinity College, Dublin, and, apparently without waiting to take a degree, entered the foreign office on 15 October 1817. His first appointment was as attaché to his uncle, the Earl of Clancarty, at the Hague.