Gildas the British historian both refer to Ireland as Scotia. It was a term that exclusively referred to Ireland up until the eleventh century when modern Scotland was first referred to as Scotia. But even up until the sixteenth century, many Latin writers continued to refer to Ireland as Scotia. From the twelfth to the sixteenth century, various scholars used to distinguish between Ireland and Scotland by using Scotia Vetus or Scotia Major meaning Old Scotia or the Greater Scotia for Ireland, and Scotia Minor or Lesser Scotia for Scotland. Insula Sanctorum or the Island of the Saints and Insula Doctorum or the Island of the Learned are names used by various Latin writers; hence the modern-day quasi-poetic description of the island as the "Island of Saints and Scholars". Pre-1919 Following the Norman invasion, Ireland was known as Dominus Hiberniae, the Lordship of Ireland from 1171 to 1541, and the Kingdom of Ireland from 1541 to 1800. From 1801 to 1922 it was part of the United Kingdom of Great Britain and Ireland as a constituent country. Irish Republic (1919–22) In English, the revolutionary state proclaimed in 1916 and ratified in 1919 was known as the Irish Republic or, occasionally, the Republic of Ireland. Two different Irish language names were used: Poblacht na hÉireann and Saorstát Éireann, based on two competing Irish translations of the word republic: Poblacht and Saorstát. Poblacht was a direct translation coming from the Irish pobal, cognate with the Latin populus. Saorstát, on the other hand, was a compound of the words: saor (meaning "free") and stát ("state"). The term Poblacht na hÉireann is the one used in the Easter Proclamation of 1916. However the Declaration of Independence and other documents adopted in 1919 eschew this title in favour of Saorstát Éireann. A slight variant of this title, Saorstát na hÉireann, was also sometimes used in later days as was the Latin Respublica Hibernica. (For an explanation continuing usage of the term Irish Republic in the United Kingdom, see Name dispute with the UK (below). Some republicans also continue to use the term because they refuse to recognise the Anglo-Irish Treaty – see below). Southern Ireland (1921–22) Southern Ireland () was the official name given to an autonomous Home Rule region (or constituent country) of the United Kingdom. It was established under the Government of Ireland Act 1920 on 3 May 1921. It covered the same