Although he stood at the helm of the Ottoman state during the last years of Sultan Süleyman’s reign and decisively shaped the trajectory of the empire in the immediate post-Süleymanic era, Grand Vezir Sokollu Mehmed Pasha remains one of the more enigmatic figures of the era celebrated as the Golden Age of Ottoman history. While many studies touch upon his political career, the profile of Sokollu Mehmed Pasha as a patron and axis of a social network encompassing a variety of social actors, ranging from artists, architects and historians, to dragomans, renegades of European origin, enterprising sailors and explorers has only recently come under closer scrutiny. This recent research has moved beyond the representations of Sokollu Mehmed Pasha as a nepotistic and shrewd Ottoman grandee and begun to reveal the portrait of a man with a complex, ambitious international political agenda. While it is often emphasized that Sokollu Mehmed Pasha was the key figure behind the re-establishment of the Serbian Patriarchate at Pec in 1557, his religious outlook and its relationship to his overall political agenda has not been closely examined. This paper will inquire into the scope and variety of Sokollu Mehmed Pasha’s patronage of religious causes and individuals with particular religious agendas. One of the particular foci will be Mehmed Pasha’s patronage of European, especially Protestant converts to Islam residing in Istanbul. These converts attached to Sokollu Mehmed Pasha’s household or dependant on him for stipends and work provided a variety of services, mostly in the domain of linguistic and diplomatic mediation with the Habsburg court. However, biographies of these converts, both official and ad hoc dragomans (tercümans) employed by the pasha, suggest that they were also involved, both in person and through their writings, in a more global religious debate that marked the early modern era, about the true religion and political regime that would guarantee spiritual salvation. Wholeheartedly supported by Sokollu Mehmed Pasha, these converts argued for Islam as the most authentic religion and the Ottoman sultanate as the only worldly authority able to realize the divine plan on earth. Moreover, these converts experimented with anti-Trinitarianism, a Christian heresy that gained popularity throughout Europe in the second half of the sixteenth century and that shared with Islam the views about humanity of Jesus and unity of God.