Jack O'Neill is a United States Air Force Colonel with
experience in special ops. O'Neil is married to Sarah O'Neill and
suffers a period of suicidal depression after his son accidentally
shot himself with O'Neill's pistol. O'Neill is recalled to active
duty and when Dr. Daniel Jackson deciphers the Stargate, he leads a
reconnaissance mission of airmen and Daniel to the other side.
O'Neil's standing order is to detonate a nuclear warhead near the
Stargate at the sign of danger, but a young boy named Skaara gives
him a renewed sense of life. After the defeat of Ra, O'Neil and his
team return to Earth while Daniel remains on the planet with his
new-found love. O'Neill was the irreverent but heroic leader of
SG-1 from its inception until his promotion to Brigadier General.
Escaping the death of his son, he was on the original expedition to
Abydos with Daniel Jackson. Once Daniel, Carter, and Teal'c
arrived, O'Neill formed SG-1 and led it for seven years until,
against all probabilities, he was promoted to Brigadier General and
made commander of the SGC. After a successful year, he was promoted
again, to Major General, and now heads the Department of Homeworld
Security at the Pentagon in Washington, D.C.