Mustafa Abdel-Jalil: Former Libyan Justice Minister, Defected from the government on Feb 21st, 2011, and declared the creation of a transitional government 5 days later. (http://www.stratfor.com/analysis/20110307-libyas-opposition-leadership-comes-focus). Named head of the National Transitional Council once it was formed on March 6th.
Abdel-Hafidh Ghoga: Benghazi based lawyer, in opposition to Mustafa Abdel-Jalil's leadership of a transitional government. Named spokesman of the NTC (ibid.)
Ali al-Essawi: Former Libyan ambassador to India, defected from the government in Febuary 2011. De facto foreign minister of the NTC (ibid)
Abdel Fattah Younis: Former Interior Minister, became military leader of NTC paramilitary. Assasinated in August 2011.