 The oldest settlement dates from the 12th century when the village, then called Magnussewo, was founded by one of the early Dukes of Masovia.In 1377, when the village was owned by Świętosław, it received certain autonomy rights (Magdeburg Rights) from Duke Siemowit IV.In 1576, as a result of war damage and fires that destroyed numerous wooden buildings, Magnuszew was demoted to the rank of a village.