Muammar Gaddafi became the "de facto" leader of Libya on 1 September 1969 after leading a group of young Libyan military officers against King Idris I in a bloodless coup d'état.
 After the king had fled the country, the Libyan Revolutionary Command Council (RCC) headed by Gaddafi abolished the monarchy and the old constitution and established the Libyan Arab Republic, with the motto "freedom, socialism, and unity".
The First Gulf of Sidra offensive was the second major rebel offensive of the Libyan Civil War.
 It was mounted by anti-Gaddafi forces immediately after their victory in the Battle of Ajdabiya.
 The offensive was meant to have the rebel forces quickly reach Gaddafi's hometown of Sirte.
The Second Gulf of Sidra offensive was a military operation in the Libyan Civil War conducted by rebel anti-Gaddafi forces in August and September 2011 to take control of towns along the Gulf of Sidra in an effort to surround Muammar Gaddafi's hometown of Sirte, which was held by pro-Gaddafi forces.
 It ended on 20 October, when Muammar Gaddafi and his son Mutassim Gaddafi were killed along with former defense minister, Abu-Bakr Yunis Jabr.
 The Gaddafi loyalists in the area were finally defeated when NTC fighters captured Sirte.
The Battle of Sirte (also spelled Surt) was the final battle of the Libyan Civil War, beginning when the National Liberation Army attacked the last remnants of the Libyan army still loyal to Muammar Gaddafi in his hometown and designated capital of Sirte, on the Gulf of Sidra.
 As of September 2011, Sirte and Bani Walid were the last strongholds of Gaddafi loyalists and the NTC hoped that the fall of Sirte would bring the war to an end.
 The battle and its aftermath marked the final collapse of the four-decade Gaddafi regime.
 Both Gaddafi and his son, Mutassim, were wounded and captured, and tortured and killed in custody less than an hour later.
 The month-long battle left Sirte almost completely in ruins, with many buildings damaged or totally destroyed.
In the Action in the Gulf of Sidra, the United States Navy deployed aircraft carrier groups in the disputed Gulf of Sidra in the Mediterranean Sea.
 Libya claimed that the entire Gulf was their territory, at 32° 30' N, with an exclusive 62 nmi fishing zone.
 Libyan leader Muammar Gaddafi asserted this in 1973 and dubbed it The Line of Death.
 The United States claimed its rights to conduct naval operations in international waters, a standard of 12 nmi territorial limit from a country's shore.
Gulf of Sidra offensive may refer to any one of three military operations launched during the Libyan Crisis:
Sidra or Sidr (Arabic: السدر‎ ‎ ) is a port about 23 km west of Ra's Lanuf in Libya.
 It is Libya's largest oil depot, shipping about 447000 oilbbl/d , and during the Cold War gave its name to the 'Gulf of Sidra', an alternative name for the Gulf of Sirte.
 Sidra Airport is directly next to the port.
The Gulf of Sidra Offensive was an offensive of the Second Libyan Civil War.
 It was launched by the Benghazi Defense Brigades on 3 March 2017, and has so far resulted in them taking control of a strip of coastal territory between the towns of Nofaliya and Ras Lanuf, which was then handed over to the Government of National Accord.
 A number of significant oil ports are located in this area, sometimes referred to as the Oil Crescent.
 The loss of the Oil Crescent has been perceived by analysts as a major blow to the power of Field Marshal Khalifa Haftar.
Muammar Mohammed Abu Minyar Gaddafi ( ;    ;  1942 20 October 2011), commonly known as Colonel Gaddafi, was a Libyan revolutionary, politician, and political theorist.
 He governed Libya as Revolutionary Chairman of the Libyan Arab Republic from 1969 to 1977, then as the "Brotherly Leader" of the Great Socialist People's Libyan Arab Jamahiriya from 1977 to 2011.
 He was initially ideologically committed to Arab nationalism and Arab socialism, but later came to rule under his own Third International Theory.
During the early stages of the Libyan Civil War of 2011, the Gaddafi regime was still in power: but there was widespread withdrawal of support from that regime by influential persons and organisations within the country.
 Among those who no longer supported the regime, the main concern they expressed was what they regarded as its use of excessive force against peaceful protestors.
 There were many resignations by ministers of the governing council and other senior officials, diplomats posted abroad, and senior military officers.
 Islamic clerics, tribal leaders, and members of the former royal family expressed their opposition, while the two leading Libyan oil companies also withdrew support for the regime.

Question: Which leading Libyan revolutionary was killed in the Second Gulf of Sidra offensive?
Answer: Muammar Gaddafi