His baptismal name was Frederick, and he was a younger brother of Godfrey, duke of Upper Lorraine, marquis of Tuscany (by his marriage with Beatrice, widow of Boniface, marquis of Tuscany).
Her baptismal name was Sophia Augusta Frederica.
His baptismal name was Guido, Giovanni being only his name in religion.
His father was a Swabian baron, Count Hartwig von Calw, and his own baptismal name was Gebhard.
At this time he changed his baptismal name of John, which was unpopular owing to its connexion with John de Baliol, for that of Robert, being crowned at Scone in August 1390 as King Robert III.