The tradition's cause-and-effect here is documented rather than legendary, which is what makes it useful. Sugawara no Michizane was a scholar from a middling family who rose on ability to Minister of the Right, was accused by Fujiwara no Tokihira of plotting to depose the emperor, demoted to a nominal post at Dazaifu in Kyushu in 901 with his sons scattered into exile, and died there in 903. Tokihira died at thirty-nine in 909. The crown prince died in 923. In 930 lightning struck the imperial palace during a drought conference, killing several senior courtiers who had been involved; the emperor fell ill and abdicated, dying weeks later. The court restored Michizane's office and rank posthumously, burned the decree of exile, and in 947 built Kitano Tenmangū. Over the following centuries the terrifying thunder deity gradually became the benign patron of scholarship. Today Kitano and Dazaifu take millions of students, and the plum blossom is his emblem because of the poem he addressed to the tree in his Kyoto garden on leaving.