Following the Shia-dominated February 14th uprising in Bahrain, groups of Sunni Muslims counter-mobilized in the streets. In reaction to the uprising and the state’s failed attempts at containing it, they voiced demands for political reform. This was something new to the political dynamics of the country. Traditionally Sunni Muslim groups in general have been loyal to the Sunni government, whereas the Shia Muslims, which constitute the majority of the population, have dominated the opposition. This thesis discusses the causes of the Sunni Muslim mobilization and how it serves to complicate rentier rule in Bahrain. It argues that Sunni Muslims who mobilized saw the situation going from unfortunate to unbearable as the violent clashes between state and opposition escalated. By casting themselves as the real victims of the conflict the Sunni Muslims felt an urgent need to act to counter the development. Their negative sentiments towards the Shia Muslim opposition resonated with the government narrative that the uprising was an expression of Iranian expansionism. This contributed both to mobilization and victimization, and illustrates how ethno-religious lines shape Bahraini politics. This thesis identifies three elements of the Sunni Muslim mobilization that may complicate the Bahraini government's ability to co-opt group formation. These are the ethno-religious dimension in Bahrain, the tension between hard-liners and moderates and the emergence of leaderless movements.