The Enochian Navy's biggest campaign was fought during the Third Civil War in 2243. When the Tech Infantry Rebels' failed coup plunged the Federation into a bloody internal conflict, the Kingdom of Enoch took the opportunity to expand its territory. In January, the Enochian Navy seized the lightly-defended border system Hrothgar (mainly as a buffer between Enoch and the Federation, since Hrothgar had few resources or population and was of little strategic or economic value). A month later it captured Valkyrie, a much more valuable system. Despite the Enoch ships being essentially antiques, they overwhelmed the Earth Fleet picket there with superior numbers.
Unfortunately, that was the high point of Enochian Naval power. In March, they invaded the Phoenix system in an attempt to capture the valuable shipyards there... and failed spectacularly, being forced to retreat after suffering heavy losses. Worse, while the bulk of the Enochian Navy was occupied in Phoenix, the Christian Federation launched a sneak attack to seize Hrothgar. Despite the Righteous Navy being even smaller and weaker than the Enochian Navy, they managed to capture or destroy the entire Enochian picket through a combination of surprise, superior numbers, and the use of suicide ships.
The setbacks at Phoenix and Hrothgar effectively ended the Enochian Navy's offensive capability, and they refocused on preserving their gains. In May, however, Earth Fleet sent a task force to retake Valkyrie. Enoch, having lost half of its navy by now, surrendered the system without firing a shot, withdrew back to their own space, and sued for peace.
The Enochian Navy's role as a deterrent to invasion of vampire space finally failed when the Federation invented the Dooms Day Device, which they used on Enoch itself in 2255. What was left of the Enochian Navy was mostly destroyed in the brief campaign of conquest that followed. The few ships that survived to be captured were scrapped or used for target practice soon afterwards, although a handful of ships were simply listed as "missing in action, presumed destroyed." Most of those were probably indeed destroyed in the supernova explosion that obliterated Enoch, but a few may have escaped to become pirates or smugglers.