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.
http://archives.math.utk.edu/
Euclid:https://mathshistory.st-andrews.ac.uk/Biographies/Euclid.html