Did Irish monks discover Iceland and Greenland?

This description certainly fits Iceland well, and early maps often label Iceland as 'Thule.' If this is a reference to Iceland, how does an Irish monk writing 50 years before the settlement of Iceland by Vikings know so much about it? read more

The oldest known source which mentions the name "Iceland" is an 11th-century rune carving from Gotland, while the oldest archeological finds indicating settlement date back to the 9th century. The first written source to mention the existence of Iceland is a book by the Irish monk Dicuil, De mensura orbis terrae, which dates back to 825. read more

Following the prevailing winds across the northernmost part of the Atlantic Ocean, they crossed it using landing points such as the Aran Islands, the Hebrides, the Faroe Islands, Iceland and Greenland as stepping stones before arriving in Newfoundland. read more

Unlike Norway, Denmark did not need Iceland's fish and homespun wool. This created a dramatic deficit in Iceland's trade. The small Greenland colony, established in the late 10th century, died out completely before 1500. read more