The Wikipedia is fantastic for questions like this.
http://en.wikipedia.org/wiki/Main_Page
Marie and Pierre Curie discovered radium in 1898.
Unfortunately the Wikipedia doesn't seem to have the history of calcium. However this site does:
http://www.webelements.com/webelemen...m/history.html
Apparently an Englishman named Sir Humphrey Davy first isolated calcium metal in 1808.