This is one of the best all around sites that I have found. It is titled “The MacTutor History of Mathematics Archive.”
http://www-history.mcs.st-and.ac.uk/~history
This is an award-winning site that links to all sorts of mathematics information.
https://mathshistory.st-andrews.ac.uk/HistTopics/History_overview
Universals: A short history is given on this site which is taken from the Internet Encyclopedia of Philosophy.
http://www.utm.edu/research/iep/u/universa.htm
Einstein:
https://mathshistory.st-andrews.ac.uk/Biographies/Einstein