After the middle ages colonisation by Norman, British and Scottish settlers created conditions for five centuries of cultural stagnation. Periods of peace and stability are necessary for the development of culture. Ireland remained separated from cultural evolution and innovation occurring in other countries. The Renaissance did not reach Ireland, it barely touched Britain. The Wilton diptych maybe, but then again it looks more like a late medieval work. The treasures of the renaissance had to be imported to Britain.
In the early 18th century a period of prosperity led to the creation of cultural institutions like the Royal Dublin Society in 1731 and the Royal Irish Academy in 1785. Robert West established a drawing school in Georges Lane. In 1757 the Dublin Society (later called the Royal Dublin Society) started a drawing school in Shaws court in Dame street and asked West to take the position of master there.
From 1660 the grand tour became popular and finished the education of many landed gentry, they brought home many artworks, paintings and venereal diseases. Artists followed wealthy tourists back to Britain, hungry for patronage and British artists learnt from them. Garret Morphy trained with Edmond Ashfield in London in 1673 and was assumed to be the first Irish born painter. The National Gallery of Ireland website says he was born in Yorkshire. Morphy admired Anthony Van Dyck although his style is similar to the Flemish portrait painter Gaspar Smitz who also painted in Ireland at the same time. Morphy painted a portrait of Oliver Plunket who was executed at Tyburn in 1681 for promoting the Catholic faith. He was hanged drawn and quartered and his severed head now resides in Saint Peter’s Church in Drogheda. The painting was reproduced in mezzotint by J. Vander Vaart, a copy of which is in the National Gallery of Ireland. I can’t work out where the painting resides, some of my searches say the National Gallery in London some say it is in private collections.