The jihadist organisation has become yet another player in the lawless North African nation, where rival authorities and militias are battling for control of territory and major oil reserves.
-- 2014 --
- November 19: The US says it is "concerned" by reports that radical extremists with avowed ties to IS are destabilising eastern Libya, having already seized vast swathes of territory in Iraq and Syria.
News reports say the eastern coastal city of Derna is emerging as an IS stronghold.
- December 27: A car bomb claimed by IS explodes outside the diplomatic security building in Tripoli without causing casualties.
-- 2015 --
- January 27: IS claims an attack on Tripoli's luxury Corinthia Hotel that kills nine people.
- February 15: IS releases a video showing the beheading of 21 Coptic Christians, all but one Egyptians, that the jihadists say they filmed in January. Egypt carries out air strikes on IS in Derna.
- February 20: IS claims suicide car bombings in Al-Qoba, near Derna, that kill 44. It says the attacks are to avenge losses in the air strikes.
- April 19: A new video shows the execution-style killing of 28 Christians originally from Ethiopia.
- June 9: IS announces it has captured Sirte, east of Tripoli.
Signup to our newsletter and follow us on Facebook and Twitter!
- July 12: The group acknowledges it has been pushed out of Derna after weeks of fierce fighting with members of the town's Mujahedeen Council.
- November 13: The US bombs IS leaders in Libya for the first time and says it killed Abu Nabil, an Iraqi also known as Wissam Najm Abd Zayd al-Zubaydi. Libyan officials identify him as the head of IS in Derna.
-- 2016 --
- January 7: A suicide truck bombing at a police school in Zliten, east of Tripoli, kills more than 50 people, the worst attack since the 2011 revolution. It is claimed by the IS.
- February 5: US officials say the number of jihadists has almost doubled in Libya to about 5,000.
- February 19: A US air strike on a jihadist training camp near Sabratha, west of Tripoli, kills about 50 people.
- February 24: Some 200 jihadists briefly occupy the centre of Sabratha, but are ousted by militias.
- March 30: The head of Libya's UN-backed unity government, Fayez al-Sarraj, arrives at a naval base in Tripoli, despite the hostility of rival authorities.
May 31: UN special envoy Martin Kobler calls on all Libya's armed groups to unite against IS.
- June 4: Unity government forces say they have retaken a jihadist air base, Al-Gordabiya, south of Sirte.
- June 5: Sarraj rules out an international military intervention on the ground.
- June 9: Unity government forces enter the centre of Sirte where clashes continue with the IS, according to a spokesman.