Fox was first launched in 1986, with three squares contained the letters "FBC" which stand for Fox Broadcasting Company.
In 1987, it introduced a more familiar logo which based on a longtime logo and the Fox wordmark was capitalized. It also featured the signature spotlights and the double pane platform under the Fox wordmark.
The familiar logo was given a more hip makeover with the Fox typing revised and the angle was changed so that the whole familiar logo faces the viewer head-on in 1993.
The spotlights were omitted, but they kept the pane underneath the Fox wordmark in 1995. Note that this may have been the shortest-lived logo to ever be used by the network.
In 1999, the 20th Century Fox spotlights were removed and only the Fox wordmark is intact.