Unidentified Star Destroyer class

An unnamed class of Star Destroyers was developed by Fondor Shipyards at the order of Supreme Chancellor Palpatine secretly in 22 BBY. Officially, the reason for it's commission was to create a new command vessel for the Republic Navy, but in actuality, it was to test the technology and design that he would possibly use on a later Star Destroyer class. It was, unofficially, the first Super Star Destroyer.

It's most noticeable feature were three cloaking devices placed in different sections of the ship.

However, the only known ship of it's class, the Xerxes, was destroyed during the Fondor shipyard assault, after sabotage by Death Watch Mandalorians in service of the Confederacy of Independent Systems. When that occurred, Palpatine expressed his anger at Count Dooku for allowing it to happen, and executed the ship's commander, who survived the destruction of the Xerxes, Captain Yarus.