Factbox - Venezuela's President Hugo Chavez

(Reuters) - Venezuela's President Hugo Chavez made a surprise return to Venezuela on Monday, saying he felt "fine" after treatment for cancer in Havana.

Chavez's return changes the political dynamics once again the OPEC member country, where politicians on all sides had been bracing for a months-long absence of the man who has dominated Venezuela for the last 12 years.

Here are some key facts about Chavez:

* Born to a poor family in the Venezuelan plains or "llanos" on July 28, 1954, Chavez once aspired to be a painter and then a professional baseball player. He often explains politics using baseball metaphors and the folksy language of the "llanos" he learned during his childhood.

* A former lieutenant colonel, Chavez spent much of his later military career conspiring with other leftist officers to overthrow the country's traditional political order. He led a 1992 coup that failed but made his reputation and propelled him towards the presidency.

* Chavez won power in a 1998 presidential vote and took office the next year. Opposition politicians and dissident troops led a coup against him in 2002, but supporters and loyal soldiers swept him back to power in less than two days. Chavez accuses the U.S. government of backing the putsch.

* Chavez has enjoyed wide backing among Venezuela's poor majority with massive social spending to expand health and education programs financed by income from oil exports. He has also cultivated support by confronting the United States, which he denounces as a decadent empire.

* He first warned in 2004 that he would shut off oil supplies to the United States if it tried to invade the Andean nation or impose a trade blockade against his country -- after he accused then U.S. President George W. Bush of backing the short-lived 2002 coup attempt. The following month, he backed away from the threat and said he did not have any intention of damaging relations with Washington.

* Inspired by his friend and mentor, Cuba's Fidel Castro, Chavez has taken Venezuela down an increasingly radical path, nationalizing large swathes of the economy and running the government with a personalized -- many would say autocratic -- style. Opponents say he has become an old-style Latin American "caudillo" or dictator, repressing critics, squandering the nation's oil wealth and ruining its economy.

* Chavez has a deliberately populist style and is famous for his strong language and long-winded speeches that often drag on late into the night. His weekly Sunday TV talk show, "Hello, President," has lasted as long as eight hours.

* Chavez announced on June 30 that he was being treated for cancer. He had been absent from public view since his initial operation in Cuba to remove a pelvic abscess on June 10. That was followed by the more serious cancer tumour extraction.

(Reporting by Caracas bureau; Editing by Eric Walsh and Jackie Frank)