In addition to researching the national (domestic) law of Ireland you will need to also research Ireland's obligations under international law.

Article 38 of the Statute of the International Court of Justice sets out the sources of international law:

The Court, whose function is to decide in accordance with international law such disputes as are submitted to it, shall apply:

a. international conventions, whether general or particular, establishing rules expressly recognized by the contesting states;

b. international custom, as evidence of a general practice accepted as law;

c. the general principles of law recognized by civilized nations;

d. subject to the provisions of Article 59, judicial decisions and the teachings of the most highly qualified publicists of the various nations, as subsidiary means for the determination of rules of law.

The most important source of international law are international conventions, also known as treaties or international agreements. This guide will provide information on finding treaties where Ireland is a party. Please see the International Legal Research Guide for more detailed information on how to conduct international legal research, including how to find other sources of international law. 

Treaty research requires finding a full-text copy of a treaty or international agreement, then checking the status to see if it has entered into force, whether a party has ratified it, or if there have been any amendments.  

Copies of full-text treaties and status information can generally be found on the depositary's website. A depositary is a government or organization to which the treaty is entrusted. Responsibilities include accepting all notifications and documents relating to the treaty, examining whether formal requirements are met, and notifying the parties of relevant acts. 

For assistance with understanding treaty terminology (e.g., signatory, reservation, accession) when looking at status information, please see the UN Treaty Glossary. 

Ireland is a member of the European Union, a political and economic union that consists of 27 member states. The EU is a supranational international organization, which means that the member states have surrendered some powers to the organization. The EU may enact rules that preempt the laws and regulations of the member states.   

Sources of EU law consist of primary legislation (i.e., founding treaties), secondary legislation (regulations, directives, and decisions), general principles of law, case law, and treaties between member states. The Official Journal of the European Union is the official gazette published every weekday that provides access to primary and secondary legislation, information, and notices. 

The Court of Justice of the European Union interprets treaties and other EU law. The decisions bind only the parties and can invalidate national legislation. A dispute raised in the Irish courts that involves European law may be referred to the European Court of First Instance and/or the European Court of Justice.