The 1647 Programme of four 370 ton fourth-rate vessels was approved by Parliament on 9 January 1647. The ships were to carry a minimum of 32 guns in peacetime and 38 guns in wartime. Each vessel would have 11 pairs lower deck gun ports and eventually an equal number on the upper deck with two pairs on the quarterdeck. The vessels would actually have varying number of guns and the dimensional data would vary considerably. Three vessels were ordered in December 1645.^[1]

The construction of the vessels was assigned to Chatham, Woolwich and Deptford dockyards. The ships would be built under the supervision of the master shipwrights of each Dockyard. As with most vessels of this time period only launch years are available. The dimensional data was so varied that it will be listed on the individual vessels along with their gun armament.^[2]