Shitennoji is one of the oldest temples in japan, and it is the first national established temple. It has been said that Shitennoji was built in AD 593 by Shotoku Taisi, a member of the imperial family and a politician.
Shotoku Taishi is one of the most famous historical figures among Japanese people, though his existence has been cast a doubt by some historians. For Japanese people, he is, in a sense, a transcended existence that is comparable to the existence of Jesus Christ for western people, though that existence does almost not have influences to today's society unlike Jesus Christ.
Shotoku Taishi swore to himself at the age of 14 that if his allied army could win the battle which they faced at the time, he would build a temple for worshipping Shitenno, the four gods of buddhism. That was the Shitennoji.
Shotoku Taishi (AD574 - 622) is known to have written the first ever Japanese Constitution and made the plan for establishing a centralized and united government centering on the emperor. He was also so eager to learn from China that he dispatched the envoys to China four times to make them learn Chinese culture and technology. Besides, he made efforts to spread the buddhism in Japan.
However, there are some unrealistic legends about him like "He flied with his horse", which has provided some historians with the thought that he was an imaginary figure.
Further more, legend has it that he was born in a stable. Todays historians are thinking that it is an influence from the Christian Gospel, with some refer to the influences from Buddhism and Chinese ancient worship. The majority of scholars, however, seem to think that although some legends were made up by writers of old historical documents, Shotoku Taishi certainly existed. For your information, his life is expressed in paintings on the wall of Edou, a part of Shitennoji's site.
Shitennoji also has its school adjacent to the westside of its site. Nevertheless, the school doesn't produce monks or priests. Shitennoji have been managing some schools ranging from elementary to university, sending their students out into non-religious companies.
Likewise other Japanese historical architectures made of wood, Shitennoji has experienced several times of burned down and reconstruction. Currently existing Shitennoji is the work of reconstruction completed in late twenties century.