The first organized form of Taoism, the Way of the Celestial Masters's school (later known as Zhengyi school), developed from the Five Pecks of Rice movement at the end of the 2nd century CE; the latter had been founded by Zhang Taoling, who said that Lao Tzu appeared to him in the year 142. The Way of the Celestial Masters school was officially recognized by ruler Cao Cao in 215, legitimizing Cao Cao's rise to power in return. Lao Tzu received imperial recognition as a divinity in the mid-2nd century BCE.