Of course, many people in Scotland and Wales wanted to keep their ancient language and culture. Many Welsh people, and many more Scottish people, suffered as the English language culture became dominant. However, this was all nothing compared to the suffering of the Irish.
English was first introduced to Ireland by the Normans who settled ordinary English speakers (rather than French) in the area known around Dublin, known as the Pale. By the time of the Tudors, however, these English-speaking areas had virtually disappeared.
Henry VIII proclaimed himself king of Ireland in 1541 and tried to introduce the Reformation to the Irish. Ireland remained Catholic but the conquest of Ireland was finally completed under Elizabeth I and James I. Both the Tudors and the Stuarts saw the use of the Irish language as a threat to their power and they encouraged the use of English. In the sixteenth and seventeenth century, the English followed a policy of simply taking land from the Irish and settling English-speakers, many of whom were from Scotland. These areas were called the Plantations.
English-speaking Protestants were rewarded; Catholic speakers of Irish Gaelic were persecuted and punished. As the united kingdom of Scotland and England became more strongly Protestant, Catholics had fewer and fewer rights.
In the seventeenth century, the British virtually completed the process of taking land from Irish Catholics in wars; about one third of the Irish population either died or left the country. From the fifteenth to the eighteenth century, thousands of Irish political prisoners were sold as slaves by the British in an astonishing act of dehumanization of one’s neighbors. Most of these ended up in the Caribbean.
Those who stayed at home were very often no better off than the slaves, however; they were governed by terror. The Protestant English-speaking people who had power in Ireland were often irresponsible and incompetent and showed no concern for the Irish Catholics; the Irish were denied political power and basic human rights. In the potato famine of 1740-1741, about 40% of the Irish population died. In the second potato famine of 1845-1852, about one million people died and about the same number of people emigrated. Ireland was actually producing lots of food at this time, but the British rulers did not allow them to have any of it!
Ireland became an English speaking country but only after many had been killed or forced to leave the country. Little wonder that the Irish were overjoyed to gain independence in 1916 after a long struggle against tyranny.