A hierarchy of the galaxy's most powerful Goa'uld
, each controlling and operating from their own region of space. As the Goa'uld have a feudal society, these areas are constantly in dispute. Various System Lords are almost constantly in conflict with one another; if one Goa'uld is forced to abandon a planet, another will often take his or her place.
The System Lords form the highest level of authority within Goa'uld society, with lesser Goa'uld, Jaffa, and human slaves in their service. They meet together on rare occasions to discuss their mutual interests and enemies.
Currently active System Lords include (but are not necessarily limited to) Anubis, Baal, Bastet, Kali, Morrigan, Olokun, Svarog, and Yu. Yu has been a member of the elite group the longest, for more than 1,000 years. Deceased Goa'uld who were once at the level of System Lord include Ra, Nirrti, Cronus, Apophis, and possibly Heru'ur.
From time to time, there has been a single System Lord who dominates the others. Ra was called the "Supreme System Lord" before his death.
Fair Game - The System Lords -- represented by Cronus, Nirrti and Yu -- negotiate with the Asgard to add Earth to the Protected Planets Treaty.
Jolinar's Memories - SG-1 and the Tok'ra learn that Sokar -- once banished by the System Lords -- is poised to defeat them all.
The Serpent's Venom - SG-1 and the Tok'ra sabotage an alliance between Apophis and Heru-ur in an attempt to return the balance of power to the feuding System Lords -- but Apophis becomes more powerful than ever.
Summit - The System Lords convene to discuss a common threat to their forces, with no knowledge of a Tok'ra plot to kill them.
Last Stand - The System Lords vote to allow Anubis back into their ranks, over Yu's objections.
Full Circle - Yu successfully manages to turn the other System Lords against Anubis and his plans for conquest of the galaxy -- but their combined fleet is decimated by Anubis's powerful new weapon.
New Order, Part 1 - System Lord representatives visit Earth to discuss negotiations for a new treaty.
New Order, Part 2 - Elizabeth Weir detains Camulus, Yu and Amaterasu when she learns that a Goa'uld ship is en route to Earth.
Reckoning, Part 1 - The System Lord empire is crippled when the superior forces of the Replicators invade our galaxy and wipe out a large percentage of their forces.
Stargate: Continuum - Baal, believed to be the last surviving System Lord, is tried and convicted by the Tok'ra, his symbiote removed and killed.