The Safavid dynasty actually ruled the greatest Persian empire since the Muslim conquest of Persia, and one of their key religious contributions was their establishment of the Twelver school of Shi'a Islam as the official empire religion. This was a massive turning point in Muslim history. In addition, let us remember the vast geographical tracts of land that they ruled. the Safavid empire at its height controlled Iran, Azerbaijan, Armenia, Iraq, Georgia, Afghanistan and the Caucasus, as well as significant tracts of Pakistan, Turkenistan and Turkey. In addition, the Safavid empire had the possession of gunpowder, which clearly helped it maintain its power and dominance.