cylon basestars
            The original Cylons were a technologically advanced reptilian race from a far corner of the galaxy.  As they died out many millennia ago, little is known of their society.  They must have been warlike and imperialistic
since at the time of their extinction they had already conquered hundreds of other worlds.  The key to the success of the early Cylon's conquests was their development, first of sophisticated robots, and then of fully
intelligent androids.  These machines were build to withstand enormous stress and to have great strength and powerful computational capacity. Armies of them swept through sector after sector of the galaxy.  But ultimately, the machines became the superiors of their creators, and the Cylons themselves were destroyed by their own machines.
            The Cylon androids, reptilian in form like their masters, continued the mission of destruction to which they had been assigned.  Machines that they were, they swept through the galaxy even more ruthlessly than their
creators.  The directives of their programming crystallized into a single Edit of Extermination, that called for the destruction of all intelligent life forms in the galaxy.
             Modern Cylons are basically human form.  The most common type is the Centurion, a heavily armored soldier capable of operation a Raider and piloting a Baseship or Dreadnought, and also adaptable to planetary
invasion and extermination.  They are not o f high intelligence, but can be cheaply mass-produced.  A common Cylon strategy, therefore, is to overwhelm the enemy with large number of Centurions, many of whom will be
destroyed, leaving a sufficient number of survivors to carry the day.
            The most advanced Cylons are from the I-L Series.  Both Lucifer, aide to Commander Baltar, and the Imperious Leader itself are of this type.  I-L series Cylons have acute reasoning abilities, and can directly monitor electronic telemetry from up to fifty sources simultaneously.  Much more than simple automatons, the I-L's at times exhibit human like drives for power.  Human cylonologists speculate that this ambition response was deliberately programmed into the I-L's to insure prompt replacement of incompetent leadership.
             The first human-Cylon contact occurred in yahren 5547, when combined human forces came to the defense of their amphibious allies, the Hasaris.  The humans were unprepared for the massive Cylon offensive, and their fleet was soon forced back to the outer defense perimeters of their own Colonies.  This was the beginning of the thousand-yahren Great Cylon War.
             The Humans proved to be the most formidable foes the Cylons had ever faced.  Lacking imagination to respond to human advances creatively, the Cylons adapted in the only way they could:  by imitation.
            The Centurions were designed to resemble Humans more and more, and their weapons were redesigned accordingly.  Human weapons advances were quickly met by Cylon copies, so that the war remained in stalemate for hundreds of yahren.  The Colonial Unification Movement and the military genius of Commander Cain had pushed the Cylons to the breaking point, when the treachery of Baltar led to the near-final destruction of humanity.
             An I-L series Cylon known as the Imperious Leader commands the vast Cylon Empire.  Although the other I-L series Cylons treat the Imperious Leader with great respect, all secretly aspire to its role.  No orderly means of
succession has been developed ; if an Imperious Leader shows weakness, it is replaced by whatever Cylon unit has the power to eliminate it.
            The first Imperious Leader engineered the overthrow of the reptilian Cylons.  Today, of all Cylons, only the Imperious Leader retains reptilian form.

Cylon attack force including basestars (double saucers) and cylon raiders