The predecessor of the Northern Department was the New York Department, which was established on June 25, 1775. This department was sometimes described as the Separate Department and the troops stationed in it were known as the "Separate Army". The original New York Department was coextensive with the Province of New York. The department's boundaries were extended to include Canada in the initial phase of the Invasion of Canada, but Canada was established as a separate department on January 17, 1776. When the Middle Department was created on February 27, 1776 the New York Department was merged into it. The Middle Department, as originally organized, included all of the colonies of New York, New Jersey, Pennsylvania, Delaware, and Maryland. The inclusion of New York in the Middle Department continued for less than two months, however. In April 1776 the Main Army moved from Boston to New York City and Washington assumed command of the Middle Department. The Northern Department was formally established from the Middle Department on April 14, 1776. The reorganized Northern Department included only that portion of the colony of New York north of the Hudson Highlands, and the present state of Vermont. The field army associated with the Northern Department was known as the Northern Army. Operations in this department did not end with Saratoga. Fighting continued in the Northern Department until the end of the war. The department was discontinued upon the death of its last commander, General Alexander, at Albany on January 15, 1783.