Zichmni
Zichmni is the name of an explorer-prince who appears in a 1558 book by Caterino Zeno of Venice, allegedly based on letters and a map (called the Zeno map) dating to the year 1400 by the author's ancestors, brothers Nicolò and Antonio Zeno. Zichmni is described as a great lord of some islands off the southern coast of Frislanda, a possibly fictitious island claimed to be larger than Ireland and located south of Iceland. According to the book, the letters provided a first-hand account of a voyage of exploration undertaken in 1398 by Prince Zichmni, accompanied  by the Zeno brothers. The book claims that the voyagers crossed the North Atlantic to Greenland. A few recent authors speculate that they may have reached the coast of North America. There is disagreement among historians as to whether to accept the Zeno letters as valid. Some proponents of the authenticity of the tale maintain that Zichmni was a Scottish nobleman named Henry Sinclair. However, other scholars have pointed to flaws in this identification and consider it extremely unlikely. The first person to identify Zichmni with Henry Sinclair was Johann Reinhold Forster in 1784.