Ministerio de Educacion, Cultura y Deporte (Spain)
La Historia De Matematicas a Traves De Los Siglos
In Spanish. Offers brief mathematical histories beginning with Egypt and Babylon up through the 19th century.
Wikimedia
Wikipedia: Timeline of Mathematics
Wikipedia gives a timeline of all of the important mathematical accomplishments from 2400 BC to 2002. Most names and concepts are linked to further information specific to that person or idea.
University of St. Andrews (UK)
University of St. Andrews: Full Chronological Mathematicians Index
This site from the University of St. Andrews has information on any mathematician you can think of and who may be found through a chronological index approach or alphabetically.