He was
called to the Bar in 1815, became
King's Counsel in 1835 and a Bencher of the
King's Inns in 1843. He became Third Serjeant in 1843, Second Serjeant in 1851 and First Serjeant from 1851 until his death. He was also appointed Chairman of the
Quarter Sessions for
County Tipperary, a position which was normally given to a practising barrister with no other official post. He was severely criticised for "legal pluralism": some of the attacks on him may reflect an objection by conservative
Protestants to the increasing number of Roman Catholic judges and Law Officers, but other attacks simply reflect the fact that he was not highly regarded as a lawyer. The office did fall vacant soon after, but Howley was passed over. In 1865 he was
knighted, a very unusual honour for a Serjeant-at-law. This appears to have been in the nature of a "consolation prize", and a recognition that at the age of seventy-six, he could not expect to advance further in his career. He died the following year and is buried in
Glasnevin Cemetery. ==Family ==