Most people are wrong. about Irish history. About 900 years ago The Gaels in Ireland ruled Scotland and took lands in England. The Vikings then arrived and attacked England and Ireland and they had more success beating the Anglo-Saxon then they had with the Irish. They took some coastal towns in Ireland, but eventually, they got beaten at Clontarf in one of the biggest Viking battles ever found in Europe.
Normans then arrived and they took over in England. They did not conquer all of Ireland.
When Ireland came under full occupation is around the late 1600s. England was invaded by William of Orange who was a ruler in Holland. The army was about 50,000 men a huge army for the day and conscripts came from Germany and Holland. They were better armed and more professional than any army in England or Ireland at the time. When William invaded Ireland he had a 4-1 advantage in numbers but the Irish put up a good fight but their commander King James was not a good leader he was a Scot and he made mistakes and they lost. The English then eventually over the next 100 years gradually took over everything.
The only thing I took from this is that the gaels are so fucking stupid that they allowed a Scot to be their King and lead them. That's because the Irish aren't good leaders and more akin to sheep. Go follow.