Various classes of Imperial warships, ranging from 900 meters up to 17,000 kilometers. Introduced during Clone Wars, the original ship was the Victory-class. The Venerators then were used, and fought with distinction in the Second Battle of Coruscant (Clone Wars). Then the Imperators replaced the Venators after the Clone Wars, with these warships being scrapped to make the Imperators, or relegated to Outer Rim duty in the Empire. Victory-IIs were introduced around this time. The Imperators have 2 subclasses, the Imperator-Is and Imperator-IIs. Then there are the Executor-classes. These "Super Star Destroyers" anything larger than Imperators are 17,600 meters. These are dwarfed by the Sovereign-classes, which are only 15 km lon, but much thicker and the largest Star Destroyer, the Eclipse-class.
Acclamator-IIs?, Victory-I, Venator, Victory-II, Imperator (Imperial), Executor, Sovereign, Eclipse. All Star Destroyer classes