What happened? Why now? And what does the future hold for this volatile region of the world? Here's everything you need to know about the leaders, the protesters and the problems in each of the nations that have been gripped by protests over these last few months.
King Hamad bin Isa Al Khalifa has ruled the tiny Gulf state since 1999, when he succeeded his father, Isa bin Salman. Upon his ascension to the throne, King Hamad began a series of political reforms, granting more rights to women and ending an era in Bahrain known for extreme repression and brutal torture.
Aided by record high oil prices in the past decade, King Hamad turned his island state from a backwater port into an affluent nation where the average home earns more than $40,000. King Hamad formed strong ties to the United States at an early age, starting with his attendance at the Army Command and Staff College at Fort Leavenworth, Kan.
Bahrain is the smallest state in the Gulf, but its sectarian divide is enormous. King Hamad and his Sunni leadership rule more than 700,000 residents, the majority of which are Shiite.
Though Bahrain is religiously tolerant, the Shiite majority has long complained of political and economic discrimination, especially the lack of representation in government. And although U.S. diplomats called King Hamad a leader who "understands that Bahrain cannot prosper if he rules by repression," in cables released by WikiLeaks, several human rights groups have criticized the recent return to using torture in interrogations.
Thousands of protesters, primarily in Shiite villages near the capital, marched the week of Feb. 14. Some, however, demonstrated under the slogan, "Not Sunni, Not Shiite, just Bahraini," implying a broader cultural cross-section is interested in changing the status quo.
After two days of a violent crackdown left at least five dead, Bahrain leaders withdrew tanks and riot police on Feb. 19. Thousands of protesters cheered at the military withdrawal, pouring back into the square in jubilation, though many remained wary of the regime's intentions and still called for a change in leadership.
Government forces were quick to open fire on peaceful protesters. As many as 50 people were injured in clashes, which occurred as hundreds of youths who had attended the funeral of a protester killed earlier began walking to the square.
The economic and political stakes for prolonged unrest in Bahrain would be huge for the entire region.
Bahrain's Sunni neighbors, notably Saudi Arabia, would be wary to see a toppling of a neighboring king, especially by a Shiite-led group. The Saudis fear a greater Iranian influence on their backdoor.
Bahrain is also a great ally of the United States, offering proximity and a strategic counterbalance to Iranian influence. Bahrain is home to a major U.S. naval base serving the Fifth Fleet and houses two U.S. patriot missile batteries, according to a 2009 secret American cable released by WikiLeaks.