1573Tenshō gannen (天正元年): The new era name was created to mark a number of regional wars. The era name was inspired by a passage from the Chinese classic Laozi: :"Those who are at peace with nature bring all under Heaven into its correct pattern" (清静者為天下正).
The era name Tenshō was suggested by Oda Nobunaga. The previous era ended and a new one commenced in Genki 4, the 28th day of the 7th month.
Events of the Tenshō era
1573 (Tenshō 1, 7th month): Ashikaga Yoshiaki lost his position as shōgun. He shaved his head, becoming a Buddhist priest. Initially, he took the priestly name Sho-san, but he eventually came to be known as Rei-o In.
1574 (Tenshō 2, 9th month): Suppression of sectarian rebellion in Nagashima.
1576 (Tenshō 3, 5th month): Takeda Katsuyori led an army into Tōtōmi Province where he lay siege to Nagashino Castle. The Tokugawa defended the castle; and Tokugawa Ieayasu sought assistance from Oda Nobunaga. In response, Nobunaga and his son Nobutada arrived at Nagashino with a large force. In the ensuing Battle of Nagashino, the Takeda attackers were forced to retreat.
February 20, 1582 (Tenshō 10, 28th day of the 10th month): A Japanese mission or embassy to Europe (Tenshō Ken'ō Shisetsu) sailed from Nagasaki, and its members would not return until 1590. It headed by Mancio Itō and organized on the initiative of Alessandro Valignano. Although less well-known and less well-documented than Hasekura Tsunenaga's diplomatic mission to the Vatican (known as the "Keichō Embassy") in 1613–1620, this historic diplomatic initiative remains a noteworthy accomplishment. The mission is sometimes referred to as the "Tenshō Embassy" because it was initiated in the Tenshō era. This venture was organized by three daimyōs of Western Japan – Ōmura Sumitada, Ōtomo Sōrin and Arima Harunobu.
December 17, 1586 (Tenshō 14, 7th day of the 11th month): Ogimachi gave over the reins of government to his grandson, who would become Emperor Go-Yozei. There had been no such Imperial since Emperor Go-Hanazono abdicated in Kanshō 5. The dearth of abdications is attributable to the disturbed state of the country and to the fact that there was neither any dwelling in which an ex-emperor could live nor any excess funds in the treasury to support him.
1586 (Tenshō 14, 12th month): A marriage is arranged between the youngest sister of Hideyoshi and Tokugawa Ieyasu.
1586 (Tenshō 14, 12th month): The kampaku, Toyotomi Hideyoshi, was nominated to be Daijō-daijin.
1587 (Tenshō 15): Gold or silver coins called Tenshō-tsūhō were minted. The gold coins (Tenshō-ōban) weighed 165 grams; and these oval shaped coins were worth 10 ryō.
1590 (Tenshō 18, 7th month): Hideyoshi led an army to the Kantō where he lay siege to Odawara Castle. When the fortress fell, Hōjō Ujimasa died and his brother, Hōjō Ujinao submitted to Hideyoshi's power, thus ending a period of serial internal warfare which had continued uninterrupted since the Ōnin era (1467).
^In the name "Keichō Embassy", the noun "Keichō" refers to the nengō (Japanese era name) after "Bunroku" and before "Genna." In other words, the Keichō Embassy commenced during Keichō, which was a time period spanning the years from 1596 through 1615.