[4] During his reign, Tenmu implemented political and military reforms, consolidating imperial power and centralizing governance.

His foreign policy favored the Korean kingdom of Silla while severing diplomatic relations with the Tang dynasty of China.

He used religious structures to bolster the imperial authority, building several Buddhist temples including Yakushi-ji and monasteries as well as strengthening ties with the Ise Shrine.

However, it was edited by his son, Prince Toneri, and the work was written during the reigns of his wife and children, causing one to suspect its accuracy and impartiality.

He was not expected to gain the throne, because his brother Tenji was the crown prince, being the older son of their mother, the reigning empress.

Tenji was suspicious that Tenmu might be so ambitious as to attempt to take the throne, and felt the necessity to strengthen his position through politically advantageous marriages.

Tenmu assembled an army and marched from Yoshino to the east, to attack the capital of Omikyō in a counterclockwise movement.

Tenmu's reign brought many changes, such as: (1) a centralized war department was organized; (2) the defenses of the Inner Country near the Capital were strengthened; (3) forts and castles were built near Capital and in the western parts of Honshū—and in Kyushu; (4) troops were reviewed; and all provincial governors were ordered to complete the collection of arms and to study tactics.

The Man'yōshū includes a poem written after the Jinshin War ended: Our Sovereign, a god, At Asuka, Emperor Tenmu was enthroned.

[16] In 675 Emperor Tenmu banned the consumption of domesticated animal meat (horse, cattle, dogs, monkeys, birds), from April 1 to September 30 each year, due to the influence of Buddhism.

[17] In the Nihon Shoki, Tenmu is described as a great innovator, but the neutrality of this description is doubtful, since the work was written under the control of his descendants.

It is said that Tenmu asked that each household was encouraged to build an altar with a dais where a Buddha-image and a sutra could be placed so that family worshiping could be held, thus inventing the butsudan.

Kugyō (公卿) is a collective term for the very few most powerful men attached to the court of the Emperor of Japan in pre-Meiji eras.

In this context, Brown and Ishida's translation of Gukanshō offers an explanation about the years of Empress Jitō's reign which muddies a sense of easy clarity in the pre-Taihō time-frame: Unless otherwise noted (as BC), years are in CE / AD  * Imperial Consort and Regent Empress Jingū is not traditionally listed.