January-March 2011
- Pro-democracy protests spread across the Middle East in the wake of the Arab Uprisings.
March 15, 2011
- A "Day of Dignity" is held when protesters call for the release of political prisoners. On the same day, a "Day of Rage" rally is held in the city of Daraa. Violence erupts in Daraa after a group of teenagers are arrested for writing political graffiti. Dozens of protesters are killed by security forces in Daraa.
May 2011
- President Bashar al-Assad abolishes martial law and subsequently introduces a new "counterterrorism" law. Syrian military troops are deployed in civilian areas.
- The United States imposes sanctions on Syria.
August 2011
- The Syrian National Council is formed.
- President Barack Obama calls upon Assad to step down.
November 2011
- The Arab League imposes sanctions on Syria.
January 2012
- Al-Qaeda establishes its presence in Syria through the rebel group Jabhat al-Nusra.
February 2012
- The U.N. General Assembly passes a nonbinding resolution endorsing the Arab League's plan for Assad to step down. When the resolution reaches the U.N. Security Council, it is vetoed by Russia and China.
- Syria holds a referendum on a new constitution, but rebel forces dismiss it as a sham.
March 2012
- Syrian troops take control of the Bab Amr neighborhood in Homs after killing hundreds of civilians in a siege.
- The United Nations estimates 8,000 Syrians have died over the course of the conflict.
April 2012
- The Syrian government promises to comply with a U.N. ceasefire on the condition that it can continue to defend itself against forces it perceives to be terrorists. The ceasefire ultimately fails.
May 2012
- An attack on Homs kills more than 100 civilians, more than half of whom are children.
June 2012
- The United Nations suspends peacekeeper patrols due to escalating violence.
July 2012
- The Syrian government threatens to use chemical weapons if foreign powers intercede in the conflict.
August 2012
- Obama refers to chemical weapons as a "red line," explaining that if Syria crosses the line and uses chemical weapons against rebel forces, the United States will intervene.
November 2012
- The Syrian National Council becomes the Syrian National Coalition to form a more cohesive front against government forces.
February 2013
- The U.N. Security Council estimates that the number of civilians killed is approaching 70,000.
- There is an influx of weapons from outside forces to support the Syrian National Coalition.
April 2013
- The jihadist militant group, ISIS (also known as ISIL) expands into Syria. ISIS grew out of al-Qaeda (the groups later split) and is one of the main jihadist government-opposition groups in Syria and Iraq. ISIS operates independently of other jihadist and rebel groups, with its own set of objectives.
June 2013
- Obama authorizes sending weapons to Syrian rebel forces in response to reported use of chemical weapons by Assad's government.
- The United Nations estimates 93,000 Syrians have been killed.
August 2013
- Assad is accused of using chemical weapons on civilians, including children. The Syrian government denies this and blames the chemical attacks on rebel forces.
- Obama seeks Congressional approval to intervene with force in Syria.
September 2013
- Obama decides not to intervene in Syria.
- The United States and Russia agree to a plan to dismantle chemical weapons in Syria.
October 2013
- Chemical weapons factories in Syria are officially out of operation.
December 2013
- A U.N. fact-finding team determines that people at the highest levels of the Syrian government are responsible for war crimes.
January 2014
- The United Nations stops counti¬¬ng Syrian deaths due to unreliable data as a result of the chaotic conditions of war.
- The first round of international peace talks regarding the Syrian Civil War begins in Geneva.
February 2014
- A second round of peace talks is held in Geneva. All parties fail to reach an agreement.
May 2014
- The Syrian military regains control of Homs.
June 2014
- Presidential elections are held in Syria. For the first time since Hafez al-Assad took power, more than one candidate is allowed on the ballot. Bashar al-Assad wins the election.
- ISIS declares an Islamic state over its controlled territories in Syria and Iraq.
July 2014
- The United Nations unanimously approves a plan to allow aid into Syria without the approval of the Syrian government.
August 2014
- The United Nations releases its first death count since its announcement in January that it would stop counting due to unreliable data: it estimates that more than 191,000 people have been killed over the course of the war.
Sources:
BBC News. "Syria Iraq: The Islamic State Militant Group." August 2, 2014. http://www.bbc.com/news/world-middle-east-24179084
Chivers, C.J and Eric Schmitt. "Saudis Step Up Help for Rebels in Syria With Croatian Arms". The New York Times. February 25. 2013. http://www.nytimes.com/2013/02/26/world/middleeast/in-shift-saudis-are-said-to-arm-rebels-in-syria.html
CNN. "Syria Civil War Fast Facts." http://www.cnn.com/2013/08/27/world/meast/syria-civil-war-fast-facts/
Laub, Zachary and Jonathan Masters. "The Islamic State." Council on Foreign Relations. May 18, 2015. http://www.cfr.org/iraq/islamic-state/p14811
Sanchez, Ray. "ISIS, ISIL or the Islamic State?" CNN. January 23, 2015. http://www.cnn.com/2014/09/09/world/meast/isis-isil-islamic-state/
The New York Times. "Video Feature: The Story of ISIS." December 16, 2014. http://www.nytimes.com/2014/12/15/world/middleeast/video-feature-the-story-of-isis.html
The New York Times. "Events in Syria: A Chronology." September 1, 2011. http://www.nytimes.com/ref/timestopics/syriatimeline.html