1. History of Mathematics: The MacTutor History of Mathematics Archive (Encyclopedia)

http://www-history.mcs.st-andrews.ac.uk/index.html

This is a complete Encyclopedia of Mathematics and very user-friendly...

There are hundreds of biographies, indexes of everything mathematical... it is awesome...

and presented by the University of St. Andrews, Scotland...


2. A Brief Visual History of Geometry: a 33 image slide show from Encyclopedia Britannica

http://linkis.com/www.britannica.com/t/3Wqli

This is also "awesome", just much briefer : )