First rate was the designation used by the Royal Navy for its largest ships of the line. Originating in the Jacobean era with the designation of Ships Royal capable of carrying at least 400 men, the size and establishment of first-rates evolved over the following 250 years to eventually denote ships of the line carrying at least 80 cannons across three gundecks. By end of the eighteenth century, a first-rate routinely carried 100 guns and more than 850 crew, and had a measurement (burthen) tonnage of some 2,000 tons.