The first written mention of the city was in 1230 as "Villa Cassa". The name probably comes from the Slavic personal name "Koš", "Koša" → "Košici" (Koš'people) → "Košice" (13821383) with the patronymic Slavic suffix "-ice" through a natural development in Slovak language (similar placenames are also known from other Slavic countries). In Hungarian "Koša" → "Kasa", "Kassa" with a vowel mutation typical for the borrowing of old Slavic names in the region (Vojkovce → Vajkócz, Sokoľ → Szakalya, Szakál, Hodkovce → Hatkóc, etc.). The Latinized form "Cassovia" became common in the 15th century.