Agincourt was a Broadside-class cruiser in the Imperial Navy during the Galactic Civil War.
Behind the scenes[]
The name Agincourt is an unusual choice for a ship in the Star Wars universe. It was probably inspired by the numerous British warships to bear the name HMS Agincourt, which in turn drew the name from a pivotal battle of the Hundred Years' War between England and France.
In that particular engagement, victory came to the vastly outnumbered english army through the use of Longbow archers who decimated much of the enemy's troops before they could close in for close quarter combat and overwhelm the smaller force. Put another way, long range weapons saved one army from otherwise certain defeat, which may help explain the use of this name for a long range artillery ship.