The Illuminati in Deus Ex

The player is directed to Morgan Everett in an attempt to find a cure for The Gray Death. JC Denton learns that Morgan Everett is in fact the leader of The Illuminati. The Illuminati (plural of Latin illuminatus, "enlightened") aim to achieve global domination, so that they can provide a balanced world in which they can  rule and control in peace. The Illuminati have been operating in secret for centuries in order to fulfill this goal. Between 1940 and 1965, The Illuminati contained a database of all the genetic codes of all the  population. Notable leaders include Morgan Everett, Stanton Dowd, Lucius DeBeers, Chad Dumier, and Nicolette DuClare.

The plan of The Illuminati was to bring the world to a state where it relied on The Illuminati, allowing a centralised government to be created. Therefore, most events in history have been intentionally caused or engineered by The Illuminati. The Illuminati planned to control the world through religion and politics, but it became evident that in the 20th century, such beliefs would be  rejected by many. Therefore, The Illuminati planned to control the world through controlling finance and technology. The Bilderberg Group and Majestic 12 were formed in order to achieve this goal.

The Illuminati lost power as a result of Majestic 12 separating from the control of The Illuminati. The Illuminati essentially lost most its power in the 21st century and Page attempted to achieve world control by using The Aquinas  Protocol.