João Das Regras
As you can read below this name is used as a pseudonym.
João das Regras, in English, literally John of the Rules, was a Portuguese jurist of the second half of the 14th century. João das Regras was born in Lisbon in an unknown date and died there on 3 May 1404. Son of João Afonso das Regras and Sentil Esteves, João das Regras became a stepson of Álvaro Pais, the chief chancellor of the Portuguese Kingdom, after his mother's second marriage.