One could infer that Ivanhoe takes place in the Middle Ages (500-1500 A.D) because the passage portrays a monarch, or a king ruling over a division of social classes (like nobles and knights. Historically this is called Feudalism). Happy to help!
It's important not to confuse the theme and the main idea. The theme is an underlying message of bravery, or hope, or love. The main idea, however, is simply what the story is about. In a way, the main idea is a tight summary of the plot.
The suffix is -fy . Hope this helps
