Shrewsbury Township was originally formed on October 31, 1693, and was created as a township by the Township Act of 1798 of the New Jersey Legislature on February 21, 1798. Shrewsbury was part of the Navesink Patent or Monmouth Tract granted soon after the creation of East Jersey in 1665. When it was formed in 1693, Shrewsbury Township covered an area of almost 1,000 square miles (2,600 km2), extending to the north to the Navesink River, south to include all of present-day Ocean County, east to the Atlantic Ocean and west to the present-day border of Monmouth County. It retained its size and scope until 1750, when Stafford Township was formed, taking away most of present-day Ocean County.
Source: Snyder, John P. The Story of New Jersey's Civil Boundaries: 1606-1968, Bureau of Geology and Topography; Trenton, New Jersey; 1969. p. 182