Commonwealth Of England The 1637 Group of warships for the Navy Royal of King Charles I consisted of two 300 ton 'pinnaces' (early frigates) intended to carry fourteen pieces of ordnance and sixteen banks of oars, which were ordered on 12 December 1636.

Their proportions (their keel length to beam ratio of 3.46 : 1) anticipated by nearly a decade the true frigates like the Constant Warwick.

[1] Their initial deployment was to the coast of Morocco, where both ships participated in an attack against the Barbary corsairs of Salé.

As built they carried thirty guns, comprising culverins[3][Note 1] and demi-culverins on the gundeck (where they had ten pairs of gunports),[4][Note 2] and sakers on the quarterdeck and forecastle (where they had four and two pairs of gunports respectively).

[6] The consensus is that in peacetime they retained 18 guns in their gundeck (of the 12 culverins and 8 demi-culverins carried in wartime), but their upper deck (created by building a complete deck linking the forecastle and quarterdeck) had just 12 sakers (4 forward and 8 aft of the unarmed waist).