(CNN)Here's a look at Yemen, a country located on the southwestern tip of the Arabian Peninsula, sharing a border with Saudi Arabia and Oman.
About Yemen
(from the CIA World Fact Book)
Area: 527,968 sq km (twice the size of Wyoming)
Area: 527,968 sq km (twice the size of Wyoming)
Population: 30,984,689 (2022 est.)
Median age: 19.8 years
Capital: Sanaa
Ethnic groups: Predominantly Arab; but also Afro-Arab, South Asian, European
Religions: Muslim (99.1%: an estimated 65% are Sunni and 35% are Shia) and small numbers of Jewish, Christian, Hindu and Baha'i (2020)
Unemployment: 27% (2014 est.)
Other Facts
Yemen is part of the Arab League.
Yemen has been mired in political unrest and armed conflict, which intensified in early 2015. Houthi rebels -- a minority Shia group from the north of the country -- drove out the US-backed government and took over the capital, Sanaa. The crisis quickly escalated into a multi-sided war, with neighboring Saudi Arabia leading a coalition of Gulf states against the Houthi rebels. The coalition is advised and supported by the United States and the United Kingdom, among other nations.
Timeline
May 22, 1990 - The Republic of Yemen is created from the unification of North Yemen, the Yemen Arab Republic and South Yemen, the People's Democratic Republic of Yemen.
May-July 1994 - A civil war between northerners and southerners begins due to disagreements between supporters of President Ali Abdullah Saleh, from North Yemen, and Vice President Ali Salim al-Baid, from South Yemen. Troops loyal to Saleh win the war.
September 25, 1999 - Saleh wins the country's first direct presidential election, with 96.3% of the vote. Opposition leaders allege tampering at the ballot box.
September 23, 2006 - Saleh wins reelection to a seven-year term with 77% of the vote.
September 17, 2008 - Ten people, Yemeni citizens and police officers, are killed in terrorist attack on the US embassy in Sanaa.
December 28, 2009 - A Yemen-based arm of al Qaeda, al Qaeda in the Arabian Peninsula (AQAP), claims responsibility for a failed bombing on a Northwest Airlines flight from Amsterdam to Detroit on December 25.
January 2, 2010 - US President Barack Obama announces a new counterterrorism partnership with Yemen, involving intelligence sharing, military training and joint attacks.
January 3, 2010 - The United States and the United Kingdom temporarily close their embassies in Sanaa after they receive word that AQAP may be planning an attack on the facilities. The US embassy reopens two days later after Yemeni forces kill two AQAP militants in a counterterrorism operation.
January 2010 - A group called Friends of Yemen is established in the UK to rally support for Yemen from the international community. They later hold meetings in London and Saudi Arabia.
January 27, 2011 - Protests break out, inspired by demonstrations in neighboring countries. The unrest continues for months, while crackdowns on protesters lead to civilian deaths.
June 3, 2011 - Opposition forces launch missiles at the presidential palace, injuring Saleh and killing several others.
September 2, 2011 - More than two million people demonstrate across Yemen, demanding that the military remove Saleh from power.
September 23, 2011 - Saleh returns to Yemen after more than three months of medical treatment in Saudi Arabia.
September 30, 2011 - Anwar al-Awlaki, spokesman for AQAP, is killed by a CIA drone strike.
November 23, 2011 - Saleh signs an agreement in Saudi Arabia transferring his executive powers to Abdu Rabu Mansour Hadi, Yemen's vice president, effectively ending his rule.
January 21, 2012 - Parliament approves a law that grants Saleh immunity from prosecution.
February 21, 2012 - Yemen holds presidential elections to replace Saleh. There is only one candidate on the ballot, Vice President Hadi, the acting president since November 2011. Hadi receives 99.8% of the 6.6 million votes cast, according to the government elections committee.
February 25, 2012 - Hadi is sworn in as president.
May 21, 2012 - During a rehearsal for a military parade in Sanaa, a suicide bomber kills more than 100 Yemeni troops and wounds more than 200.
May 23, 2012 - Friends of Yemen pledges more than $4 billion in aid to help the country fight terrorism and boost its economy. The amount is later increased to $7.9 billion. There are delays, however, that hold up delivery of the funds, according to Reuters.
December 5, 2013 - Militants attack a Defense Ministry hospital in Sanaa. They ram the building with an explosives-laden vehicle and gunmen battle security forces inside. At least 52 people are killed, including four foreign doctors, according to the government.
December 15, 2013 - Parliament calls for an end to drone strikes on its territory three days after a US missile attack mistakenly hits a wedding convoy, killing 14 civilians.
February 10, 2014 - State news reports that Hadi has approved making Yemen a federal state consisting of six regions: two in the south, and four in the north. Sanaa is designated as neutral territory.
September 21, 2014 - Hadi, Houthi rebels and representatives of major political parties sign a ceasefire deal. The United Nations-brokered deal ends a month of protests by Houthis that essentially halted life in Sanaa and resulted in hundreds of people being killed or injured.
January 17, 2015 - Houthi rebels kidnap Hadi's Chief of Staff Ahmed bin Mubarak in a push for more political power. He is released 10 days later, according to Reuters.
January 20, 2015 - Houthi rebels take over the presidential palace.
January 22, 2015 - President Hadi resigns shortly after the prime minister and the cabinet step down. Houthis say they will withdraw their fighters from Sanaa if the government agrees to constitutional changes including fair representation for marginalized groups within the country. No agreement is reached.
February 11, 2015 - The United States and the United Kingdom suspend embassy operations in Yemen.
March 20, 2015 - Terrorists bomb two mosques in Sanaa, killing at least 137 and wounding 357. ISIS claims responsibility for the attack.
March 22, 2015 - Houthi rebels seize the international airport in Taiz.
March 26, 2015 - Warplanes from Saudi Arabia, UAE, Kuwait, Bahrain, Qatar and other countries strike Houthi rebel targets.
December 6, 2015 - The governor of the city of Aden and six bodyguards are killed in a car bombing. ISIS claims responsibility.
December 18-19, 2015 - At least 100 people are killed as violence erupts in the Harath district of Hajjah, a strategic border near Saudi Arabia.
April-August 2016 - Direct peace talks between the warring parties take place in Kuwait, but fail after Houthi rebels reject a UN proposal aimed at ending the war. Yemeni government officials leave the discussions shortly afterward.
November 28, 2016 - The Iranian-backed Houthi movement forms a new government in the capital. Abdul Aziz Habtoor, who defected from Hadi's government and joined the Houthi coalition in 2015, is its leader, according to the movement's news agency Saba.
December 18, 2016 - A suicide bomber strikes as soldiers line up to receive their salaries at the Al Solban military base in the southern city of Aden. The strike kills at least 52 soldiers and injures 34 others, two Yemeni senior security officials tell CNN. ISIS claims responsibility.
January 29, 2017 - US Central Command announces that a Navy SEAL was killed during a raid on a suspected al Qaeda hideout in a Yemeni village. The Navy SEAL is later identified as William Owens. The Pentagon reports that 14 terrorists were killed during the raid. Yemeni officials say civilians got caught in the crossfire and 13 people died, including eight-year-old Nawar Anwar Al-Awalki, the daughter of Anwar Al-Awalki. The raid was authorized by US President Donald Trump, days after he was sworn in as commander in chief.
February 8, 2017 - Two senior Yemeni officials tell CNN that the government has requested that the United States stop ground operations in the country unless it has full approval.
May 15, 2017 - Save the Children reports that 242 people have died of cholera as an outbreak spreads through Sanaa and beyond.
October 16, 2017 - US forces conduct airstrikes against two ISIS training camps in what a defense official tells CNN are the first US strikes specifically targeting ISIS in Yemen.
November 4, 2017 - Houthi rebels fire a missile at the King Khalid International Airport in Riyadh. The Saudi government says that their military intercepted the missile before it reached its target. The Saudis carry out airstrikes on Sanaa in response.
November 6, 2017 - Saudi Arabia blocks humanitarian aid planes from landing in Yemen. The move is in retaliation for the attempted missile strike on Riyadh.
December 4, 2017 - Saleh is killed by Houthi rebels as he tries to flee Sanaa.
December 6, 2017 - Trump issues a statement that he has directed his administration to call for an end to Saudi Arabia's blockade.
December 21, 2017 - The International Committee of the Red Cross announces that one million cases of cholera have been reported in Yemen since the outbreak began during the spring. More than 2,200 people have died, according to the World Health Organization. It is the largest outbreak of the disease in recent history.
April 3, 2018 - Speaking at a UN Pledging Conference on Yemen, UN Secretary General Antonio Guterres notes that, in its fourth year of conflict, more than three-quarters of the population, 22 million, require humanitarian aid. Regarding hunger alone, "some 18 million people are food insecure; one million more than when we convened last year."
August 3, 2018 - The World Health Organization warns that Yemen is teetering on the brink of a third cholera epidemic.
August 9, 2018 - A Saudi-led coalition bombs a school bus, killing 40 boys returning from a day trip in the northern Saada governorate. Fifty-one people are killed in total. Later, munitions experts tell CNN that the bomb, a 500-pound laser-guided MK 82 bomb made by Lockheed Martin, was sold as part of a US State Department-sanctioned arms deal with Saudi Arabia. The Saudi coalition blames "incorrect information" for the strike, admits it was a mistake and takes responsibility.
November 20, 2018 - Save the Children says that an estimated 85,000 children under the age of 5 may have died from extreme hunger or disease since the war in Yemen escalated in early 2015.
December 6, 2018 - The opposing sides in Yemen's conflict begin direct talks in Sweden, the first direct discussions between the parties since 2016.
December 18, 2018 - A ceasefire reached in Sweden between Yemen's warring parties goes into effect at midnight (4 p.m. ET December 17) in the strategic port city of Hodeidah.
February 2019 - A CNN investigation reveals that Saudi Arabia and the United Arab Emirates have transferred US-made weapons to al Qaeda-linked fighters, hardline Salafi militias, and other groups on the ground in Yemen. The weapons have also made their way into the hands of Iranian-backed rebels, exposing some of America's sensitive military technology to Tehran and potentially endangering the lives of US troops in other war zones.
May 2019 - A CNN investigation exposes the theft or "diversion" of food aid, some of which is being stolen by Iranian-backed Houthi rebels, on a scale far greater than has been reported before.
June 2019 - The Armed Conflict Location & Event Data Project (ACLED) finds that the total number of reported fatalities in Yemen is more than 91,000 since 2015.
June 12, 2019 - A missile fired by Houthi rebels strikes the arrivals hall of Abha International Airport in Saudi Arabia, injuring 26 people. On July 2, a second attack occurs when Houthi rebels execute a drone strike on the same airport, injuring nine civilians. according to the Houthi-run Al-Masirah news agency.
August 11, 2019 - A spokesperson for Yemeni separatists tells CNN that they have taken control of Aden, which had been the seat of the Saudi-backed government since Houthis took over Sanaa in 2014.
January 19, 2020 - At least 80 Yemeni soldiers attending prayers at a mosque are killed and 130 others injured in ballistic missile and drone attacks by Iran-backed Houthi rebels, according to the UN Special Envoy for Yemen.
December 26, 2020 - Yemen's new 24-member cabinet, the power-sharing government brokered by Saudi Arabia, is sworn in. The new cohesive government will have equal representatives from Yemen's internationally recognized government and southern separatists, their coalition allies in the war against the Iran-aligned Houthi rebels.
February 12, 2021 - US Secretary of State Antony Blinken announces the removal of Yemen's Houthi rebels from the US list of foreign terrorist organizations, effective February 16, reversing the Trump administration's January 2020 designation that faced bipartisan backlash from politicians and humanitarian organizations.
April 2, 2022 - Yemen's Iran-backed Houthis and their rival Saudi-led coalition agree to a nationwide truce. It is the most significant step towards ending the hostilities since the war began seven years ago, and a win for UN and US mediators who for the past year have been trying to engineer a permanent peace deal. The renewable two-month truce is meant to halt all military operations in Yemen and across its borders.
October 2, 2022 - After a rare six months of relative calm, the truce between Yemen's warring sides expires. The two-month truce had been renewed twice but ends after the two sides fail to renew their deal.