Sailors in Christopher Columbus’s home town knew about North America more than a century before the explorer discovered the continent, Italian researchers have claimed. An account by Genoan sailors of a verdant land beyond Greenland “where giants live” has been found in a history of the world written around 1340 by an Italian friar — 152 years before Columbus set foot in the Americas in 1492.

“This astonishing find is the first known report to circulate in the Mediterranean of the American continent, and if Columbus was aware of what these sailors knew it might have helped convince him make his voyage,” said Paolo Chiesa, who led the research at the University of Milan.