Courts
Justiciar’s Courts
The Justiciar and council exercised judicial functions. Over time, a specialised judiciary developed, and most judicial business became a matter for the courts of justice. There remained a number of cases still dealt with by the Justiciar and council.  These concerned particularly,  quarrels between magnates.
Cases, where the common law provided no remedy, were attracted towards the Justiciar, although laterally, they moved towards the chancery. They were formally brought to the council by petition.
The Justiciar’s court later developed into the equivalent to the English King’s bench. The chief governor journeyed through the country for a considerable period attended by the council. Justices acting under various commissions held sessions.
Justice was done locally by persons working under limited commission. There appears to have been commissions of gaol delivery, commissions of assize, sometimes held by professional judges either alone or in association with others, and sometimes by nonprofessional judges. Circuits of justices of assize appear to have been organised as in England.
The exchequer was fixed, but its officials were sent out to do exchequer business and collect taxes and King’s debta.
Development of Professional Courts
By the middle of the 13th century, a permanent bench was established in Dublin together with the itinerant courts. By the end of the 13th century, there was a chief justice and several lower ranking judges. The judges presiding at that court,  in the latter part of the 13th century also acted as itinerant justices.
The bulk  of their business dealt with the standard common law writs. The majority of pleas related to land  dowry and minors.  A lesser number  concerned trespasses, appeals, debts and moveable goods.
As in England, liberties were granted in which the crown had more limited jurisdiction, reserving only certain key important pleas or causes of action/ crimes. Other pleas or claims were reserved to the liberty court. With the fragmentation of crown control in the later 13th and 14th century, the liberties extended.
Kings Bench
The Dublin’s King Bench corresponded with the Kings’ Bench in London. The bulk of King’s bench business concerned real actions which apart from assizes were not within the scope of the justiciar’s court. The King’s bench also dealt with contractual or semi-contractual issues of debt, detinue, and covenant. A certain rivalry with the exchequer also exists in these areas.
The court had jurisdiction to reviews of errors of lower courts. Actions and writs could be taken to challenge the verdict of an assize before justices. There was overlap with the jurisdiction of the justiciar’s court. An assize might be  transferred from the justiciar’s court if it could not be concluded within the county, as an alternative to adjourning it  the justiciar’s next court,
In some cases, the justiciar himself came to the bench in relation to the difficult matters. Generally, however, the chief justices of the bench presided. There was a chief justice and two or more puisne judges.
By the late 13th century, the first examples of Irish case preceding by appeal to the English courts are found. Some of the cases took place by bypassing the Irish court and by the late 13th century, there were examples of the justiciar protesting this.
Exchequer
The exchequer existed in Ireland since the late 12th century. It did not initially equate to that in England, but by the end of the 13th century, it seemed to have exercised judicial functions including hearing of common pleas. At that stage there was a treasurer, a chancellor, two barons, and a remembrancer. They dealt with certain pleadings relating to land and actions for damages and the recovery of monies.
The exchequer was the first department to develop out of the council. It was the financial department. A clerk was given the title of treasurer at the beginning of the 13th century. Rolls of issues and receipts were kept by the latter half of the 13th century. A special class of Barons were appointed to hold pleas of the exchequer. They passed judgment on debts due by subjects to the crown.
The Exchequers Court was concerned principally with quasi-public law matters. However, it had a rival jurisdiction based a legal fictions with that of the King’s Bench in relation to debt and related matters. The justiciar sometimes went to the exchequer court to deal with unusually difficult matters.
Chancery
The Irish Court of Chancery was established in 1232 with the appointment of the Bishop of Chichester as the chancellor for life. The duties were broadly correspondent to that of the English office. He was custodian of the Irish seal and a member of the Justiciar’s council. Writs emanate from his office. He was custodian of records. He had one clerk in the exchequer’s office and one in the Justiciar’s court to keep the rolls.
In England, the chancery commenced as secretarial department of the King’s household. Writs of the King issued from the Justiciar or the English chancery in the early 13th century. The chancellors were often clerics.
A separate Irish chancery commenced in 1232. English writs remained valid in Ireland and persons could be summoned before English courts. By the end of the 14th century; attempts  were made to bring the Irish chancery in line with English chancery.
By the 15th century in England, the equitable jurisdiction of chancery substituted petitions, which would otherwise have gone to the council in parliament. However, in Ireland, the practice of petitions to parliament continued for much longer.
The chancellor developed jurisdiction over time, parallel to that in England. By the beginning of the 17th century there were  courts with two sides, the equity side and the  common law side. The  Master of the Rolls in Ireland did not have judicial functions until the Union in 1801.