In the 1940s and 1950s, Ireland had concluded bilateral visa waiver agreements with Western European countries. Ireland participates in some of the police cooperation agreements that are part of the Schengen Agreement. From 2020, Ireland will participate in certain aspects of SIS II, the second generation of the Schengen Information System – see “Police and Security” below for more information. Directive 2004/38/EC of the European Parliament and of the Council of 29 April 2004 recognises the right of citizens of the Union and their family members to move and reside freely within the territory of the Member States, which defines the right to free movement of citizens of the European Economic Area (EEA), including the European Union (EU) and the three members of the European Free Trade Association (EFTA) Iceland, Norway and Liechtenstein. Switzerland, which is a member of EFTA but not of the EEA, is not bound by the directive, but has a separate bilateral agreement on the free movement of persons with the EU. The Schengen agreements should provide for uniform border rules for all Member States. The Schengen visa, for example, grants its holders a stay of up to 90 days in the region. In other words, a Schengen visa can be used to travel through the 26 countries that have signed the agreement for a maximum stay of 90 days within 180 days. To better understand the situation, we want to give you a bit of background. Internationally known as the Northern Ireland Conflict, a political and nationalist conflict that began in the 1960s and was fuelled by historical events. One of the key issues was the constitutional status of Northern Ireland. Unionists and loyalists, mostly Protestants, wanted Northern Ireland to remain in the United Kingdom.
Irish nationalists and republicans, mostly Catholics, wanted Northern Ireland to join a united Ireland. One of the main advantages of the EU is that citizens can travel between states without a passport, unless they want to enter the UK or Ireland, both of which are not signatories to the Schengen Agreement, which guarantees free movement between EU member states. In 2014, Ireland and the United Kingdom agreed on a common Anglo-Irish visa system (BIVS). Under the agreement between Ireland and the United Kingdom, citizens of the following countries holding a valid British visa, validated by BIVS and having authorised immigration to the United Kingdom, may travel to Ireland without a visa for a maximum period of 90 days (or until their current authorisation to enter/remain in the United Kingdom), whichever is shorter). Like those eligible for the Visa Waiver Program, they can enter Ireland from a country other than the UNITED Kingdom as long as their visa and permit to stay in the United Kingdom have not expired.  The Republic of Ireland, also known as Eire, is not part of the Schengen area, but is part of the EU. In fact, Ireland is just a handful of countries that are in the EU, but have never joined Schengen. This makes things a bit confusing for many people, including many Europeans. The Schengen Agreement aims to establish uniform border rules for all countries in the area. Once you have entered a Schengen country, you can travel to one of the other countries if you do not exceed the maximum of 90 days throughout the area. If you are an EEA national and currently live in Ireland, you may need a Schengen visa to travel to the Schengen area, even if you have a valid Irish Residence Permit (IORP).
You should inquire with the embassy of the country you wish to visit. A Schengen visa is intended for short-term stays in the Schengen area or for passage through the Schengen area of a duration not exceeding 90 days in a period of 180 days. . . .