Complex sentence: After the third treasure voyage, Admiral Zheng He returned to Nanjing in 6 July 1411 and presented the Sinhalese captives to the Yongle Emperor.
Split into simpler sentences: After the third treasure voyage, Admiral Zheng He returned to Nanjing in 6 July 1411. Thereafter, he presented the Sinhalese captives to the Yongle Emperor.