The Principal Solicitor for Ireland was one of the Irish Law Officers in the sixteenth century. The office originated in a rather unusual way, from a personal contest between two rivals for the Office of Solicitor General for Ireland, Patrick Barnewall and Walter Cowley, but it survived for some decades to take some of the burden of work from the senior Law Officers. Since both the Solicitor General and the Principal Solicitor were colloquially referred to as the Solicitor, there is some confusion as to who held which office at which time.
The office was apparently created on the personal initiative of Thomas Cromwell in 1537, in an effort to heal the Barnewall-Cowley feud, which he saw as weakening the position of the English Crown in Ireland. Cowley had made great efforts to force Barnewall to relinquish the office of Solicitor General, but Cromwell's compromise solution was to create a more junior office for Cowley. Cowley was disgraced and removed from office in 1546, but the Law Officers' heavy workload seemingly justified retaining a Principal Solicitor until 1574 when the office seems to have lapsed. No definite reason for the disappearance of the office can be given, although Elizabeth I is known to have had a very poor opinion of all her Irish Law Officers at this time, and possibly she preferred to leave this most junior office unfilled.