In the Old DC Universe, Nabu the Wise was a Lord of Order who fought arduously against the Lords of Chaos, in a classic plight of good vs evil. However, in the 1980's Dr. Fate miniseries we learn that it is not quite so black and white. The following history is taken from the DC Wikia page:
are an organization of disembodied God-like being capable of wielding nearly infinite power. As their titles suggest, the Lords are champions of chaos and discord, laboring to bring about the - the Fourth Age of Man. Their primary adversaries are the , who seek to maintain universal balance throughout reality. Each organization effects change on Earth through the use of select agents, which they in turn bestow great power unto. The Lords of Chaos have employed agents such as , and even the former hero known as to meet their goals.
Chaos and Order have been fighting a cyclical battle for eons. First Order is dominant, then Chaos, then destruction and renewal and then it starts over again. Originally, the struggle was depicted as one between Good (Order) and Evil (Chaos); it is currently depicted as a balance between stagnation and anarchy.
The two opposing forces are bundles of mystical energy who usually depend on servants to accomplish their goals. They can take physical form by possessing a living being, as in the case of or , or empower humans to act as their agents, as in the case of Terataya and T'Charr (a Lord of Order and a Lord of Chaos respectively), who empowered Hawk and Dove to act in their stead.
A Lord of Order and a Lord of Chaos were also sent to the as representatives of their realms. Kilderkin of Order manifested as a lidless box with a servant djinn holding it, and Shivering Jemmy of the Shallow Brigade of Chaos as a young blonde girl with a balloon.
In the 1980's miniseries it is revealed that the balance between Order and Chaos is just that. The fight between Order and Chaos is more about maintaining balance rather than a plight between good and evil and the Lords of Order at that time are willing to lay down their fight and let chaos bring in the Kali Yuga so as to restore an age of order in the future which would occur after the age of chaos ends it's cycle.
An interesting little tidbit to add to this is a small portion of a book that I'm reading by Dr. Michio Kaku about physics and parallel worlds. In this paragraph I'll be noting below, he writes about Three Laws of Thermodynamics, the second law having to do with chaos:
"The second law is the most mysterious and most profound. It states that the total amount of entropy (chaos or disorder) in the universe always increases."
I thought that was very interesting as it almost describes the coming age of man or Kali-Yuga. Let's hope that Nabu is somewhere out there battling to save us from this ever increasing chaos. =)