An imperial edict in 764 CE did officially place Buddhism above Shinto, but for the majority of the ordinary population, the opposite was probably true.
The spread continued with the full support of Emperor Temmu (r. 686-697 CE) who built yet more temples, had more copies of sutras made, and who used monasteries as depots for official population and tax records. 724-749 CE) was even more ambitious and set out to build a temple in every province, each with its own seven-storied pagoda, a plan that raised taxation to brutal levels.
Major temples were built at the then capital Nara, too, such as Todaiji, finally completed in 752 CE in a project supervised by the celebrated monk Gyogi (668-749 CE).
Shotoku famously drew up a new constitution (or, perhaps more accurately, an ethical code) in 604 CE called the Sincerely reverence the three treasures.
The three treasures, Buddha, the Law and the Priesthood, are the final refuge of the four generated beings, and are the supreme objects of faith in all countries. But if they do not betake them to the three treasures, how shall their crookedness be made straight?
Buddhism was introduced to ancient Japan via Korea in the 6th century CE with various sects following in subsequent centuries via China.
It was readily accepted by both the elite and ordinary populace because it confirmed the political and economic status quo, offered a welcoming reassurance to the mystery of the afterlife, and complemented existing Shinto beliefs.
Emperor Shomu was also important as he began the strategy of an emperor abdicating in favour of his chosen successor and then joining a monastery but still pulling political strings behind the latticed screens in what became known as 'cloistered government'.
At the same time as endorsing Buddhism, the Japanese elite was also wary of its powers and particularly concerned that a charismatic individual might abuse the reverence of the populace and form a following which could threaten the political stability of the state.
What man in what age can fail to reverence this law? (Henshall, 499) True to his own declaration, Shotoku built many temples and monasteries, formed a body of artists to create Buddhist images, and he was himself a student of its teachings, writing commentaries on three sutras.
During his reign, Shotoku built 46 Buddhist monasteries and temples, the most important of which were the Shitennoji, Hokoji (596 CE), and Horyuji.
At the same time Shinto gods acquired Buddhist names (Ryobu Shinto) so that, for example, the sun goddess Amaterasu was considered an avatar of Dainichi; and Hachiman, the god of war and culture, was the avatar of the Amida Buddha.