American political cartoon by Thomas Nast titled "The Usual Irish Way of Doing Things", depicting a drunken Irishman lighting a powder keg and swinging a bottle. Published 1871-09-02 in Harper's Weekly
According to wikipedia:
Negative English attitudes towards the Gaelic Irish and their culture date as far back as the reign of Henry II of England. In 1155 Pope Adrian IV issued the papal bull called Laudabiliter, that gave Henry permission to conquer Ireland as a means of strengthening the Papacy's control over the Irish Church. Pope Adrian called the Irish a "rude and barbarous" nation. Thus, the Norman invasion of Ireland began in 1169 with the backing of the Papacy. Pope Alexander III, who was Pope at the time of the invasion, ratified the Laudabiliter and gave Henry dominion over Ireland. He likewise called the Irish a "barbarous nation" with "filthy practises".
Even the Catholic church betrayed the Irish and still do today as story after story comes out about child abuse in Catholic institutions. Irish people were compared with apes and said to be raging drunks. White slavery still exists today as millions of children and young adults are kidnapped and forced into prostitution or even raped within institutions (see Tory pedophile scandals).
After almost four centuries, following the declaration of the independence of the Church of England from papal supremacy and rejection of the authority of Rome, a new basis for the English monarch's legitimate claim to the rule of Ireland was needed: the Crown of Ireland Act 1542 therefore established a sovereign Kingdom of Ireland with Henry being given the title of King of Ireland. There has been some controversy over the authenticity of the Laudabiliter.
As a result of the Irish War of Independence, most of Ireland left the United Kingdom in 1922 and became the Irish Free State, an independent country which still retained the British monarch as its head of state. The remaining six north-eastern counties continued as Northern Ireland within the United Kingdom, but with their own parliament and system of government. Despite these fundamental changes, the 16th-century Act remained unamended on the statute books.
The Irish Free State adopted a republican constitution in 1937, although its remaining ties with the British monarchy were not formally broken until 1949. However, the Tudor Act remained on the republic's statute books until formally repealed in 1962.