The Arab Spring movement began in Tunisia in 2010.
The movement was sparked when 26-year-old Mohamed Bouazizi set himself ablaze as a protest against government repression. That action resulted in widespread protests and unrest, until the country's president was forced to resign. The actions in Tunisia inspired other pro-democracy movements throughout the Arab world.
This video (2:21) serves as a good introduction to the Arab Spring reform movements.
NPR's report on the one-year anniversary of Bouazizi's death is located here, and you can see the Guardian's terrific interactive timeline here.
A recent report in the online Cipher Brief provides historical context to the Arab Spring movements. That article concludes that the once-promising movement for reform and democracy has all but failed, except for in Tunisia, the nation in which this all began. The report summarizes the history of the Arab Spring Movement generally, then focuses on developments since it began in five Arab nations. Noting the rise of Islamic State terrorism and the resulting refugee crisis, the author concludes her report by discussing current steps being taken to bring stability to the region.