Hampden County is a non-governmental county located in the Pioneer Valley of the state of Massachusetts, in the United States. As of the 2010 census, Hampden County's population was 463,490. Its traditional county seat is Springfield, the Connecticut River Valley's largest city, and economic and cultural capital. Hampden County was split from Hampshire County in 1812, because Northampton, Massachusetts was made Hampshire County's "shire town" in 1794; however, Springfield—theretofore Hampshire County's traditional shire town, dating back to its founding in 1636—grew at a pace far quicker than Northampton and was granted shire town-status over its own, southerly jurisdiction. It was named for John Hampden. To the north of Hampden County is modern-day Hampshire County; to the west is Berkshi