The Syrian civil war: Timeline and statistics

It is over 12 years since the conflict in Syria began. The conflict has killed more than 350,000 people and caused the displacement of half the Syrian population. Chemical weapons have also been deployed.

Syrian President Bashar al-Assad, aided by Iran and Russia, now controls most of Syria and is likely to remain in power. His position was further strengthened by the Arab League re-admitting Syria as a member in May 2023; Syria had been suspended from the League in 2011.

This research briefing gives a timeline of main events, statistics on the humanitarian and economic effects of the war, UK participation and aid, and a list of further reading and regularly updated resources on the conflict.

The Commons Library research briefing, Syria’s civil war in 2023: Syria back in the Arab League provides analysis on the current state of the conflict and the Assad Government, the role of foreign powers in Syria, and prospects for peace.

Casualties in Syria

Due to issues in recording, access, and partiality in the information available, it is unlikely the true figure of those killed and injured will ever be known.

In June 2022, the UN published updated estimates on the number of civilians killed in Syria. It estimated the civilian death total was 306,887 from March 2011 to March 2021.

Refugees and displaced people

The total pre-war population of Syria was around 21 million. More than half this population is now displaced from their homes, either internally within Syria or as refugees abroad.

As of December 2022, there were around 6.8 million internally displaced people living in Syria. Around 80% have been displaced for at least five years.

Refugees first started leaving Syria in large numbers in 2012, with the UN High Commissioner for Refugees recording around 730,000 Syrian refugees in that year. In June 2023, the UN Refugee Agency (UNHCR) recorded 5.3 million Syrian refugees and asylum seekers registered globally.

From 2011 to June 2022, just over 34,000 Syrians have been granted asylum or another form of humanitarian protection in the UK. Around three fifths of them (20,300) were resettled through the Vulnerable Person Resettlement Scheme (VPRS), a programme set up in 2014 to resettle vulnerable people displaced by the Syrian conflict (see section 2.3 of the briefing for data sources).

Humanitarian needs of the population

The UN Office for the Coordination of Humanitarian Affairs reports there are 15.3 million Syrians in need of humanitarian assistance in 2022. This is the highest since the conflict began. This includes around 12 million people who are estimated to be food insecure.

Syria has also seen substantial economic disruption. In 2017, the World Bank estimated the proportion of the population living in extreme poverty rose from 12% of the population in 2007 to 63% in 2016. Economic losses were estimated to total US$442 billion from 2012 to 2020.

UK aid to Syria

The UK has provided a total of £3.8 billion in official development assistance (ODA) to Syria from 2011 to 2022. ODA is aid intended to promote the economic development and welfare of developing countries. 

Since 2011, Syria has been one of the largest recipients of UK bilateral ODA in Asia. 

In March 2021, the UK Government announced a reduced aid pledge for Syria, of at least £205 million for 2021, compared to £300 million for 2020. For 2022, the UK announced a reduced pledge, of £158 million. All plans are subject to change and in previous years the government has exceed its pledges to Syria. For 2023, the Government has pledged £150 million for Syria and a further £43 million to Turkey and Syria following the February 2023 earthquakes.

UK military activity

Since August 2014, the UK has conducted airstrikes in Iraq and Syria against Daesh/Islamic State (IS), under Operation Shader, and provided military support to the US-led coalition. Operations in Syria began in December 2015.

As of July 2021, the RAF has flown 8,700 sorties and released 4,300 precision weapons (eg, missiles) to target IS across the region.

As of 31 March 2023, one member of the UK Armed Forces has been killed in action during Operation Shader and three have suffered battle injuries. A further five military personnel died on operation, but not in hostile action.

The most recent figures to 2021/22 show that the total cost of Operation Shader has amounted to £2.5 billion in real terms (2022/23 prices) since 2014. The cost of operations peaked in 2017/18 and has since fallen by around 67%.

Islamic State fighters in Syria/Iraq

In 2017, the UN estimated that more than 40,000 foreign fighters from 110 countries travelled to join IS in Iraq and Syria, and that 5,600 from 33 states had returned home. Many remain in Syria, either in custody or at large.

The number of UK citizens who have fought with IS in Iraq and Syria is uncertain—in 2019, the Government estimated they numbered 900. In 2018, the Government said that of the 900:

• 40 had been prosecuted because of their actions in Syria (4%)
• 180 had been killed (20%)
• 540 had returned to the UK (60%). Note in 2019, the Home Office reported around 400 had returned (44%)
• This implies around 180-320 remained in Syria (20%-36%).

The Library briefing, Returning terrorist fighters (March 2019) has more on policy debates on how to deal with returning fighters and terrorists.

Update log

July 2023: Updated timeline and statistics for 2023

September 2023: Added information on August 2023 protests (page 7), aid corridors (pages 12 to 13) and UK aid spending plans from 2022/23 and spending in 2022 (page 16).