Calvaert, Denis or Denys (both: dənēˈ kälˈvärt) [key], 1540–1619, Flemish mannerist painter in Italy, where he was known as Il Fiammingo. He studied in Antwerp and later in Bologna under Prospero Fontana. While a student he assisted in the execution of frescoes in the Vatican. On returning to Bologna he established a school, where he taught Guido Reni and Domenichino. Most of Calvaert's carefully drawn works, painted in smooth enamellike colors, are in the churches and national museum of Bologna.