Fortress building took off in the sixteenth and seventeenth centuries, starting in Italy where Charles V fought his wars against the French king and then in the rebellious Netherlands during the Eighty Years' War. The dimensions of the ideal fortress were first written about in the Dutch language by Simon Stevin in 1594.
This GeoGebra book contains the animations developed for my website [url]http://www.fransvanschooten.nl/Stevin.htm[/url].