Zheng He generally sought to attain his goals through diplomacy, and his large army awed most would-be enemies into submission. However, a contemporary reported that Zheng He walked like a tiger and did not shrink from violence when he considered it necessary to impress foreign peoples with China's military might. He ruthlessly suppressed pirates, who had long plagued Chinese and Southeast Asian waters. For example, he defeated Chen Zuyi, one of the most feared and respected pirate captains, and returned him to China for execution. He also waged a land war against the Kingdom of Kotte on Ceylon, and he made displays of military force when local officials threatened his fleet in Arabia and East Africa. From his fourth voyage, he brought envoys from 30 states, who traveled to China and paid their respects at the Ming court.