The Government of Ireland defines the Irish diaspora as all persons of Irish nationality who habitually reside outside of the island of Ireland. This includes Irish citizens who have emigrated abroad and their children, who are Irish citizens by descent under Irish law. It also includes their grandchildren in cases where they were registered as Irish citizens in the Foreign Births Register held in every Irish diplomatic mission. Under this legal definition, the Irish diaspora is considerably smaller—some 3 million persons, of whom 1.47 million are Irish-born emigrants. Given the island of Ireland's estimated population of 6.8 million in 2018, this is still a large ratio.