köken: As masculine, a patronymic surname, genitive singular of the masculine given name Ματθαίος (Matthaíos). The female surname, from the genitive singular of the male's surname (father's or husband's).
köken: Originally a patronymic form Mats + -son "son of Mats". Strangely a less common variant of Mattsson since the spelling Mats is more common than Matts.