The Illuminati is a secret society but they were secret only to protect themselves from persecution by the Roman Catholic church. It is a powerful organization that is comprised of very intelligent and respected scientists, philosophers, and logical thinkers. Many members are even said to dabble in mystical properties like magic which further strengthens some tales of the Illuminati having a Satanic branch in their organization.
The original Illuminati group was founded in Bavaria in the 18th century by Adam Weishaupt, an anti-clerical professor who wanted to limit the interference of the Church in public life. He based his secret society on the Freemasons, with a hierarchy and mysterious rituals, and named it the Order of Illuminati to reflect the enlightened ideals of its educated members. The Illuminati was stamped out by a government crackdown on secret societies in the late 1780s, but rumors that it continued to survive as an underground organisation have persisted into the modern day.
However, during those years, the Illuminati secretly rejoined and became the society that they are known to be now. A group that want to create a one world government, or New World Order, with themselves in charge. The Illuminati are generally comprised of people who are well known in the public such as celeberties, politicians, democrats, capitalists, and even cultists. And as a result, they are well endowed in the study of demonic arts and black magic. They will kill anyone, anywhere, at any time to get what they need and to ensure their plans are unknown to the public, and for them to be regarded as a myth rather then real.
The Illuminati are known to be in control of everything, the music industry, film industry, pharmaceutical (legal industry), medical industry, colleges, banking institutions, Wall Street and the Political System. Their symbol is even on the world's currency. The group achieved a tight control of the world's economy through the international bankers and hope to use this to subject and steer the world's economy and power to whichever direction they desire. They are acclaimed to have used Karl Marx's manifesto and Karl Ritter's antithesis towards brainwashing and initiating an opposing division of the human race with the aim of facilitating destruction of each other through opposition and wars.
Most of the major wars and economic depressions/recessions of the past 100 years were carefully planned out by the Illuminati. Some of these include: The Spanish-American War, World War I, World War II, The Great Depression, the Rise of Nazi Germany, Korean War, Vietnam War, 1991 Gulf War and French Revolution. The Illuminati are said to be currently orchestrating the events that will lead to the third World War. This in turn will finally usher in the utopia that they desire and the One World Government that they have been aiming to achieve for hundreds of years.