From 1983 to 1989 General Noriega ruled Panama with an iron fist, but contrary to a misconception spread by lazy journalists, he was never actually president of the country. He was merely commander of the Panamanian Armed Forces, a position that was nominally subservient to the country's elected president. Panama actually went through seven different presidents during Noriega's career as head of the military. Most were obedient puppets of the General, and Noriega's people rigged the elections to keep it that way.
In 1989 Panama's parliament, also largely controlled by the General, declared Noriega "maximum leader of national liberation." The act was in response to a contested presidential election that had happened earlier, in which the ant-Noriega candidate won. Noriega of course ruled the election invalid, and dispatched his goon squad to beat the poor man's face in with a lead pipe.
The United States viewed Noriega's despotism with increasing concern, especially once the General began to turn his aggression towards American soldiers stationed in the US-controlled Panama Canal Zone. Noriega's high profile role in international narco-trafficking was similarly troubling, considering the ruling Republican Party had made much of its commitment to the "war on drugs" and cracking down on dealers both at home and abroad. In December of '89 President George H. W. Bush ordered the invasion of Panama. Noriega was deposed, and then captured by US forces. For the last 17 years he has been held as a prisoner of war in a Florida prison.
When he is freed he says he wants to go back to Panama, but it's likely that will just result in more prison time. Panama has a number of outstanding warrants for his arrest, and he has already been found guilty in absentia for a number of crimes committed during his tenure as army chief. It is also possible the United States may chose to extradite him to France, where he is also wanted on a number of outstanding charges.
Noriega became Commander of the Panama Armed Forces in 1983, shortly after the former commander, General Omar Torrijos died in a mysterious plane crash. The conspiracy theorist set argue the plane crash was orchestrated by the CIA because the Americans wanted to bring Noriega to power. When he was a lower-ranking soldier Noriega was an active CIA informant and sold classified information from his government to the United States.
The current president of Panama, Martín Torrijos, is the son of the late General.