The saints of Ireland derive from the various túath, tribes or peoples, who lived on the island of Ireland. The vast majority of these saints lived during the 4th—10th centuries, a period in which Ireland was known as the "land of saints and scholars"—it produced many missionaries. The introduction of Christianity into Ireland was during the end of the 4th century. Its exact introduction is obscure, though the strict ascetic nature of monasticism in Ireland, suggests a connection to Coptic monks from Egypt. Although there were some Christians in Ireland before him, Patrick from Britain played a significant role in its full Christianisation. Some of the best known saints are the Twelve Apostles of Ireland and Brigid of Kildare.