In the English-speaking world this name has been occasionally given since the early 20th century. It started rising in America after the variant Lorelai was used for the main character (and her daughter, nicknamed Rory) on the television series Gilmore Girls (2000-2007).
Pulci was likely inspired by the Arthurian legends and as such may have created the name as a masculine form of Morgana, which is the Italian form of Morgan 2. Alternatively, he may have derived the name from the Old French adjective morgant (also found spelled as morjant) meaning "proud, haughty", which is a variant of the Old French adjective mordant, itself ultimately derived from the Old French verb mordre meaning "to bite". Also compare the noun morgue meaning "arrogance, haughty attitude".
A known real-life bearer of this name was Morgante Baglioni (died in July 1502), a member of the Baglioni family, which was a noble family that ruled the city of Perugia in the 15th and 16th century.