Answer:
Léonin
Pérotin
John of Forneste
Guillaume de Machaut
Explanation: Guillaume de Machaut lived in the 1300
Léonin lived in the mid 1100 until the start of the 1200
John of Forneste lived in the mid 1100, and died in the 1239
Pérotin was born aroun 1160, and died in 1230
Bassed on this, the list from earliest to latest would be:
Léonin, Pérotin, John of Forneste, Guillaume de Machaut