Middletown was incorporated in September of 1651 under the place's original Native American name, Mattabeseck. The name was changed to Middletown in 1653 and was a part of Hartford County when the first four counties in Connecticut were established in 1666. Middletown was incorporated as a city in 1784 and became a part of Middlesex County in 1785, when the new county was formed from portions of Hartford and New London Counties. The First Church in Middletown was organized November 4, 1668. Chatham (East Hampton) was originally a part of Middletown and the East Middletown parish, formerly a part of Chatham, was incorporated as Conway in 1841, but was later renamed Portland.