Frisland wasn’t always a phantom island. The name originally referred to Iceland. Christopher Columbus visited Iceland in 1477, and reported it was called "Frislanda" by the natives; but in 1558 a book published by the Italian historian, Nicolò Zeno, changed that, and for the next 100 years, Frisland appeared on maps as an entirely separate island, south of Iceland.
Zeno claimed he found a map and some old letters belonging to his ancestors, Nicholas and Antonio Zeno. The letters told how Nicholas set off from Venice in 1380 on a voyage to England and was blown off course and stranded on an island between Great Britain and Iceland called Frislanda, which is described as being larger than Ireland.
Nicholas was rescued by the Ruler of Frislanda, and made Admiral of the Ruler’s fleet. Together they conquered the Shetlands. Nicholas then began to explore the northern ocean, and found Engroneland (Greenland). Nicholas died in 1396, and his brother Antonio took his position as Admiral.
Antonio reported in a letter that an old fisherman had told him a story about being blown out 1000 miles into the Atlantic to Estotiland, where he stayed for 5 years before traveling south to Drogeo, which was inhabited by cannibals. Antonio and Zichmni set sail to find these lands, but found Icaria instead.
The debate continues about the authenticity of the Zeno tale. Some believe that Antonio Zeno and Zichmni were the first Europeans to find America. Others believe that the whole tale was a complete fabrication based on existing information from existing maps, in order to claim "discovery" of the new lands. Contemporary Venetian court documents place Nicolò as undergoing trial for embezzlement in 1394 for his actions as military governor of Modone and Corone in Greece from 1390–1392. He wrote his last will and testament in Venice in 1400, many years after his alleged death in Frislanda around 1394.