Not long before the onset of the Brood War, Napoleon was part of an Alpha Squadron force under General Edmund Duke carrying out survey missions, mapping potential colony worlds and re-establishing contact with isolated colonies. This changed with orders from Arcturus Mengsk, Duke leading Alpha Squadron to the world of Bhekar Ro to secure an alien artifact. Upon arrival, protoss and zerg forces were observed in battle against each other. With the arrival of Alpha Squadron, the battle soon became a three-way one.
Napoleon opened fire with its laser batteries and Yamato Cannon, partnering up with Norad III in the case of the latter. However, it was later trapped in a stasis field by a protoss Arbiter and upon its dissipation, was set upon by a flight of interceptors. Napoleon sustained heavy damage but managed to limp back to the Alpha Squadron line.
In truth, Napoleon had only delayed its destruction as a few days later, a strange energy creature launched itself from the planet. Napoleon fired its Yamato Cannon, along with Alpha Squadron's remaining battlecruisers, but this only served to empower it. As it swept past, the creature vaporized, absorbed and digested the ships, leaving only chunks of molten debris.
Napoleon is named after Napoleon Bonaparte, the famous French emperor and military leader of the late 18th/early 19th centuries.