Darius I was the second ruler of the Twenty-seventh Dynasty. He was son of Hystaspes and a member of the Cyrus family. He was in Egypt while Cambyses ruled and Darius treated the Egyptians with respect and goodwill. During his reign he undertook the completion of the canal that extended from the Nile to the Red Sea. He also expanded the Serapeum at Saqqara as well as erected a large temple of Amun in el-Kharga, a southwestern oasis. During his reign there was the defeat of the Persians in the battle of Marathon. This showed that the great empire was not invincible and a revolt in Egypt followed.