John I of Portugal was known as "Fond Memory" (de Boa Memória) due to his well-remembered reign. He was also referred to as "the Good" (o Bom), "the Great" (o Grande), and more rarely, "the Bastard" (Bastardo), especially in Spain.
Unraveling the Reign of John I of Portugal: The Pioneering Monarch of the House of Aviz