European exploration of Africa
One of the ships under command of Diogo Dias arrived at a coast that was not in East Africa. Two years later, a chart already showed an elongated island east of Africa that bore the name Madagascar. But only a century later, between 1613 and 1619, did the Portuguese explore the island in detail. They signed treaties with local chieftains and sent the first missionaries, who found it impossible to make locals believe in Hell, and were eventually expelled.
Mariana Islands
The first European to see the island group was the Portuguese explorer Ferdinand Magellan who on March 6, 1521, observed a string of islands and sailed between two of them during a Spanish expedition of world circumnavigation. Historically, the southern village of Umatac, Guam has been credited as the site of Magellan's landing, however, scholarly study of the navigator's diary, now kept in preservation in the Philippines, revealed a drawing of the islands with a tiny island to the south of a much larger island above it. The described placement of the islands made it much more likely that Magellan had actually sailed between Guam and Cocos Island, and not Guam and Rota, as originally thought. This discovery meant that Magellan could not have landed in Umatac, but more likely in a northern location like Tanguisson or Tumon Bay.