Third rate in the context of "HMS Europa (1765)"

HMS Stirling Castle was a 70-gun third rate ship of the line of the Royal Navy, built at Chatham Dockyard to the 1733 proposals of the 1719 Establishment, and launched on 24 April 1742.

The "seventy-four" was a type of two-decked sailing ship of the line, which nominally carried 74 guns. It was developed by the French navy in the 1740s, replacing earlier classes of 60- and 62-gun ships, as a larger complement to the recently developed 64-gun ships. Impressed with the performance of several captured French seventy-fours, the British Royal Navy quickly adopted similar designs, classing them as third rates. The type then spread to the Spanish, Dutch, Danish and Russian navies.

The design was considered a good balance between firepower and sailing qualities. Hundreds of seventy-fours were constructed, becoming the dominant form of ship-of-the-line. They remained the mainstay of most major fleets into the early 19th century. From the 1820s, they began to be replaced by larger two-decked ships mounting more guns. However, some seventy-fours remained in service until the late 19th century, when they were finally supplanted by ironclads.