The following report provides an in-depth, empirically focused, overview of contentious mobilization dynamics before and during the Syrian Uprising. The report describes the period between the beginning of Bashar al-Assad’s rule in 2000 until the end of 2012. Instead of an extensive chronological overview, the report is structured along a thematic “periodization”. It therefore focuses on a limited number of key issues and transformative events in the development of Syrian contentious mobilization. The report argues that two aspects stand out in the Syrian case of Arab Spring mobilization. First, the importance of societal structures in defining options available to both protesters and the regime. Second, the importance of cognitive signaling (the resonance of a certain event on a population, sometimes referred to as “thin diffusion”) at key turning points in the uprising. Both the social structures and cognitive signaling were crucial in defining (perceived) possible avenues for contestation before and during the uprising.