During the reign of the successor of the Participazio, Pietro Tradonico, Venice began to establish its military might which would influence many a later crusade and dominate the Adriatic for centuries, and signed a trade agreement with the Holy Roman Emperor Lothair I, whose privileges were later expanded by Otto I. Tradonico secured the sea by fighting Narentine and Saracen pirates. Tradonico's reign was long and successful (837 – 864), but he was succeeded by the Participazio and it appeared that a dynasty might finally be established.