How to create a knowledge organiser
Decide on your categories: maps, timeline, key people, characters, dates, concepts, formulae, themes etc.
You must have a vocabulary section with definitions AND examples of the word in use.
The information should be brief enough to be 'quizzable'.
Start adding information and then edit down to keep the KO to one page.
If you have to include several maps or diagrams then it might be a double sided page. Remember - this is the basic foundation of the topic. Studnets will build conceptual understanding on top of this foundation.