and Saichō founded the Shingon and Tendai schools of Buddhism, respectively. One or both of them are thought to have brought back the first tea seeds to Japan during this trip. Saichō, who returned in 805, is often credited for being the first to plant tea seeds in Japan, although the documentary evidence is uncertain. The book Kuikū Kokushi records that in 815, a Buddhist abbot served tea to Emperor Saga. This is the earliest reliable reference to tea drinking in Japan. Subsequently, the emperor is said to have ordered the establishment of five tea plantations near the capital. The reign of Emperor Saga was characterized by his sinophilia, which included a passion for tea. He was fond of Chinese poetry, much of which praised the benefits of tea. Emperor Saga's poetry, and that of others at his imperial court, also make references to the drinking of tea. Subsequent writings from the Heian period indicate that tea was cultivated and consumed on a small scale by Buddhist monks as part of their religious practice, and that the imperial family and members of the nobility also drank tea. The practice, however, was not yet popular outside these circles. In the three centuries after Emperor Saga's death, interest in Tang Chinese culture declined, as did the practice of drinking tea. Records from this period continued to recognize its value as a medicinal beverage and stimulant, and there are mentions of it being consumed with milk, a practice that subsequently died out. The form of tea consumed in Japan at this time was most likely , which was the standard form in China during the Tang dynasty. The world's first monograph on tea, Lu Yu's The Classic of Tea, was written a few decades before the time of Kūkai and Saichō. In it, Lu Yu describes the process for steaming, roasting, and compressing the tea into bricks, as well as the process of grinding the tea into powder and stirring it to a froth in hot water prior to consumption. This procedure is thought to have evolved into the method of preparing powdered matcha that later emerged in Japan. Eisai and the popularization of tea The Zen monk Eisai, founder of the Rinzai school of Buddhism, is generally credited for popularizing tea in Japan. In 1191, Eisai returned from a trip to China and brought back tea seeds which he planted on the