The Mauryan Empire lasted from c.321 - 185 B.C. It was founded by Chandra Gupta Maurya (r. c.321 - c.297 B.C.), who unified most of India from east to west.
After receiving a military education, Chandra Gupta gathered mercenaries and took power, becoming king of the Magadha kingdom in 325. After Alexander the Great left India, Chandra Gupta took over the Punjab in 322. His son Bindusara succeeded him (r. 297 - 272 B.C.) and extended the empire further. It reached its limits under Ashoka (r. 272 - 232 B.C.). The final Mauryan king was assassinated in 184 B.C.
Source: "Chandra Gupta." Encyclopedia Britannica. 2009. Encyclopedia Britannica Online. 8 Feb. 2009 <http://www.search.eb.com/eb/article-9019967>.