For those interested in historical curiosities and adventure, one of my favorite books is an old one called Conquest by Man, by Paul Herrman. Although more than half a century old and out of date on many issues, it still is one of the more well-done books of its kind that I have ever read. It is not an overly sensationalized book. It simply bears out, in many cases, the saying that fact can be stranger than fiction. It has interesting information on the Vikings (e.g., that the Roman Catholic Church recognized a bishop of Greenland in the 11th century, long before Columbus) and numerous other topics, such as the Egyptians traversing the Cape of Good Hope in the 6th century B.C., 2000 years prior to Bartholomew Diaz (in 1488). Still more than worth a read in spite of its age.
Yep, there was a bishop in Gardar.
http://en.wikipedia.org/wiki/Gar%C3%B0ar,_Greenland
There is an intriguing mention of Erik, the bishop of Gardar, sailing to Vinland in 1121, but nothing more was ever heard from him.