日本にお茶を広めた人物が、嵯峨天皇です。中国風の書が得意で、書道の名手「三筆」にも数えられている天皇です。嵯峨天皇は弘仁6年（815）に命令を出し、京都周辺で茶を栽培させ、毎年献上させる仕組みを作らせました。さらにこの後、京都の内裏の北東にも茶園が作られました。宮中の仏教行事である「季御読経」でも、僧侶にお茶が振る舞われています。平安時代には、お茶を飲む文化が宮廷にも広まっていたのです。

Emperor Saga (784 – 842) is thought to have been responsible for promoting tea drinking in Japan. He was a good calligrapher in the Chinese style and is known as one of the Three Excellent Brushes.
He commanded that tea be planted around Kyoto and established a system of offering tea as tribute to the court in 815. Later he had a tea plantation made in the north-eastern part of the Imperial Palace grounds
The popularity of tea at the court does not seem to have been long-lasting, but tea is found on religious occasions during the Heian period. Buddhist rituals called Kinomidokyô (seasonal chanting) were performed every year at the court, and tea was served to the monks.