9151
Chevaliers , or knights in the Middle Ages , engaged in what were usually non-physical and non-marital relationships with women of nobility whom they served .
 time: Middle Ages
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
Answer:
 time: Middle Ages