Very little is known of the Tholian Assembly, other that their government is known as the Assembly and that Tholians as a species are silicon-based life-forms preferring environments deadly to all known humanoid species. The Empire's lack of information is not unique amongst the major galactic powers. The vaunted Romulan Tal'shiar and even the efficient and effective Federation Diplomatic Service are unable to uncover anything we do not already know. The Tholians are xenophobic, isolationists to the extent that they have refused all attempts at normalized diplomatic relations with any major government. Any incursions into their space are met with swift and violent retribution until all invaders are expelled or destroyed-more often the latter.
Despite their xenophobia and isolationism, they are also opportunistic. Occasional signs of political unrest can quite often veil an armed incursion. These incursions are never full-scale and are intended to seize a small amount of territory. Yet it is unclear what the Tholians do with the territory they seize or even why they seize choose system over another, as many of their targets have scant resources and of no strategic value. Once the Assembly annexes new territory, they are defended as zealously as any other system under Tholian control.
Long-range sensor probes confirm that the core area of Tholian space is a stellar nursery, a large nebula in which new stars are forming. Planetary systems we have identified are usually very young as well, with Class C, Class F, and Class H planets on the whole, all of which incapable of supporting humanoid life. Rare expeditions returning from Tholian space have reported planets rich in mineral resources, but located within a vast territory replete with an inordinate number of subspace anomalies discovered. Until a means is found to neutralize the considerable risks presented by these unpredictable anomolies, the costs of seizing their territory far outweigh the benefits.
Tholian vessels are constructed of hyper-lineated crystalline-lattice materials. This exotic materials technology affords them extremely durable hull structures, more so even than Gorn starships. They utilize phaser-like beam weapons, and have somehow managed to duplicate (either through theft, or, less likely, their own research) Klingon heavy disruptor technology. Despite the availability of such potent weapons systems, their most formidable weapon is the Tholian Web Cannon. This technology is uniquely Tholian, and scientists from both the Klingon and Romulan Empires have been unable to determine how it is created or what specific types of energy it utilizes. The affects, however, are well documented. The most effective tactic to be used against Tholian forces-specifically when encountering their web technology-is long-range slashing attacks designed to stay well out of range of the Web generators.