Most died from hunger and disease, which has ravaged the poor Arab country, but many have been caught in the crossfire between the Saudi-backed government and Iran-backed rebel militant Houthis.
Tensions between the two groups hit a tipping point on Dec. 4 when Houthi rebels shot and killed Yemen's former president Ali Abdullah Saleh.
Saleh, who held various positions of power in Yemen for 33 years, had been "playing factions off each other" for years, former Yemeni ambassador Mohamed Qubaty told Al Jazeera.
In May 2015, Saleh officially announced his alliance with the Houthis, and even helped them seize control of large land areas, including Yemen's capital Sanaa.
But on Dec. 2, Saleh flipped his allegiance by offering to turn a "new page" with Houthi rival Saudi Arabia. He called the Houthis a "coup militia," which they saw as the ultimate betrayal and the reason for his assassination.
Yet Saleh's death is just the latest incident contributing to turbulent conditions in Yemen.
The Saudi-backed government first faced rebel Houthis in the 1990s
Yemen's complex history is one of conflict and political rivalry that has continued for nearly a century.
The Houthi movement, officially known as Ansar Allah (translation: supporters of God), began in the 1990s as a theological movement that preached peace and tolerance in Yemen.
But in 2004, the group picked up arms and declared war on the government. An uprising occurred and government forces killed the Houthi's leader.
Yemeni officials accused the Houthis and other Islamic opposition parties of trying to overthrow the government, but Houthi leaders dismissed the accusation and claimed they were defending themselves. They have long said they faced social and religious discrimination as well as political marginalization.
For the last decade, Houthi rebels and Yemeni government forces continued to clash periodically. Other factors, including an insurgence by a powerful Al Qaeda branch in Yemen and infighting between local tribes have fostered conflict and strife for years in the region.
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A former Houthi spokesperson told local news in 2013 that the group's ultimate goal is to build a "striving modern democracy" in Yemen.
Yemen's presidents have struggled
In 2012, President Saleh stepped down and formally handed power over to his deputy, Abed Rabbo Mansour Hadi, in an internationally brokered move to foster stability in the region.
Hadi struggled to keep Yemen afloat, which faced an increased presence of, and attacks by, Al Qaeda — some of which targeted government officials. Corruption was widespread and, at the same time, a third of the country lived below the poverty line and more than half were unemployed.
In 2014, the increasingly militant Houthis took advantage of Hadi's struggling government and seized control of Yemen's capital Sanaa.
A bloody civil war broke out.
A Saudi-led coalition supporting the government stepped in
Countries felt an international response was necessary.
In 2015, Saudi Arabia led a coalition of nine African and Middle East countries to intervene, backing President Hadi.
The coalition received logistical and intelligence support from the US and its allies, and launched air strikes targeting Houthi strongholds. It also implemented a naval blockade, limiting resources and aid into Yemen.
And a humanitarian crisis broke out
Since then, continued air strikes and the country's tight blockade have affected lives in Yemen where it is nearly impossible for food, water and fuel to pass through.
According to UNICEF one child dies every 10 minutes from preventable causes like hunger and disease,
The United Nations has tried to broker peace agreements on several occasions, but with little success. In May, the UN's envoy for Yemen told the security council that a peace deal was urgently needed, but confessed a deal was "not close" to being accepted by the warring sides who refuse to compromise.
In November, Saudi Arabia partially relaxed its crippling blockade to let aid deliveries through, but it had little effect on the country's starving residents.
Relations deteriorated even further this week
On Dec. 2, former President Saleh offered to mediate the conflict and "turn a new page" with the Saudi-led coalition in exchange for stopping air strikes and ending the blockade that has crippled the country, according to the BBC.
However, Houthi rebels, who had formed an unlikely alliance with Saleh, saw the move as a "coup" against "an alliance he never believed in," the BBC added.
Last weekend, a convoy Saleh was traveling in came under deadly fire from Houthi rebels. His death was confirmed on Dec. 4.
What happens next?
With Saleh dead and his allied forces facing an intensified battle with Houthi fighters, the future of war-torn Yemen is uncertain, and hopes of putting an end to the bloody civil war look bleak.
According to analysts, the Saudi-led coalition's fight against the increasingly brazen Houthis will likely intensify, Al Jazeera reported.
Joost Hiltermann, International Crisis Group's Middle East program director, told Al Jazeera that the breakdown of the Houthi-Saleh alliance will "increase fragmentation and conflict by adding layers of revenge."
Houthi leader Abdul Malik al-Houthi celebrated Saleh's death as a victory against the Saudi-led coalition in which "the conspiracy of betrayal and treason failed."
Saleh's son, a potentially powerful figure in Yemen's politically unstable climate, vowed on Dec. 5 to lead a campaign against the Houthi movement.