He was an itinerant Chinese philosopher and sage, and one of the principal interpreters of Confucianism. Supposedly, he was a pupil of Confucius's grandson, Zisi. Like Confucius, according to legend, he travelled throughout China for forty years to offer advice to rulers for reform. During the Warring States period (403–221 BC), Mencius served as an official and scholar at the Jixia Academy in the State of Qi (1046 BC to 221 BC) from 319 to 312 BC. He expressed his filial devotion when he took three years leave of absence from his official duties for Qi to mourn his mother's death. Disappointed at his failure to effect changes in his contemporary world, he retired from public life.