East Hanover Township is a township in Morris County, New Jersey, United States. As of the 2010 United States Census, the township's population was 11,157, reflecting a decline of 236 (-2.1%) from the 11,393 counted in the 2000 Census, which had in turn increased by 1,467 (+14.8%) from the 9,926 counted in the 1990 Census. The manufacturing plant of Mondelēz International (formerly Nabisco) and the pharmaceutical company Novartis are located in East Hanover.The name "Hanover" was adopted by the Township of Hanover on December 7, 1720, in honor of the British King George I of the German dynastic House of Hanover. The boundaries of East Hanover are defined by the joining of two rivers, the Whippany River to the west and north and the Passaic River to the east and north. This geographic effect led to the early name of East Hanover, "Hanover Neck." Since the creation of Hanover Township in 1720, its size has been considerably decreased as the population of the area has increased. Originally encompassing large portions of Morris County and parts of both Sussex and Warren County, Hanover Township became too unwieldy for a single local government and municipalities split off from the township over time.