Wedding guest Sandrine Tamara Steiner attended the wedding and shared a photo of the 36-year-old London lawyer/activist in the role of officiator.
Clooney, 53, was also in attendance. According to People, the wedding took place on a "a grassy ledge overlooking Florence and the surrounding countryside under a canopy of grape vines. The estate stretches out for 600 acres and features vineyards and olive groves."
Keep in mind, the actor has a lovely Italian villa in Lake Como not too far from here. Perhaps the couple picked up a tip or two!