Peregrinus' text on the magnet is entitled in many of the manuscripts of it Epistola Petri Peregrini de Maricourt ad Sygerum de Foucaucourt, militem, de magnete ("Letter of Peter Peregrinus of Maricourt to Sygerus of Foucaucourt, Soldier, on the Magnet") but it is more commonly known by its short title, Epistola de magnete ("Letter on the Magnet"). The letter is addressed to an otherwise unknown Picard countryman named Sygerus (Sigerus, Ysaerus) of Foucaucourt, possibly a friend and neighbor of the author; Foucaucourt borders on the home area of Peregrinus around Maricourt, in the present-day department of the Somme, near Péronne.