The Bucharest summit of the Three Seas Initiative (TSI) signalled that this regional cooperation format is coming of age. The summit gathered delegates from all TSI countries (Austria, Bulgaria, Croatia, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia, and Slovenia), eight of which were represented by heads of state. The significance of TSI is acknowledged by the European Commission (EC). Germany took part in the TSI summit for the first time and the U.S. for the second time. The participation of senior officials from international financial institutions in the TSI Business Forum, as well as the decision to set up the Three Seas Fund was a welcome signal to the business community.