The landmass now known as Ireland used to be called, in around the 4th to 6th centuries, "Scotland".

This is because Scotia directly translates to Scotland. According to the Isidore of Seville, a Spanish Bishop and Scholar, an English monk, "Scotia et Hibernia eadem terra est," (this is in Latin), and when translated to English, means, "Scotia and Hibernia are the same country", with Hibernia being the classical Latin name for Ireland. The reason Scotland is now named so is because the inhabitants of Ireland migrated in the Dal Rita to southwestern Scotland in the 5th and 6th centuries, and being known as the Scots, they carried the name of their location with them. If any of this is wrong, please correct me.