, also known as Yoshifushi or Yoshifuji, was a Japanese samurai, daimyo and the 13th shà Âgun of the Ashikaga shogunate who reigned from 1546 to 1565 during the late Muromachi period of Japan. He was the eldest son of the 12th shà Âgun, Ashikaga Yoshiharu, and his mother was a daughter of Konoe Hisamichi (later called , Keijuin). When he became shogun in 1546 at age 11, Yoshiteru's name was Yoshifushi (sometimes transliterated as Yoshifuji); but some years later in 1554, he changed his name to the one by which he is conventionally known today. His childhood name was Kikubemaru (). His younger brother Ashikaga Yoshiaki became the fifteenth shà Âgun.
After his father, Yoshiharu, was forced to retire in 1546 over a political struggle with Hosokawa Harumoto, Yoshiteru became Sei-i Taishà Âgun, albeit a puppet shà Âgun like his father. Yoshiteru was only 11 at the time and his investiture ceremony was held at Sakamoto, à Âmi Province, outside Kyoto.
Yoshiteru had barely been confirmed as shà Âgun when his father Yoshiharu made a truce with Harumoto to return to Kyoto. Yet, Harumoto's retainer Miyoshi Nagayoshi parted with Harumoto to take the side of Hosokawa Ujitsuna and the two Hosokawa started a war that drove out Yoshiteru, his father Yoshiharu, and Harumoto as well, from Kyoto. In 1550, Yoshiharu died in à Âmi, unable to return to Kyoto.
In 1552, Yoshiteru made a peace with Nagayoshi to return to Kyoto. However, the next year, Yoshiteru and Harumoto started a war against Nagayoshi to remove his influence. With the help of Rokkaku Yoshikata, the war initially went well for Yoshiteru but he was driven out of Kyoto again in 1558 with a counterattack from Nagayoshi. Nagayoshi did not press on after the victory to kill Yoshiteru for fear of being accused of killing a shogun, and instead signed a truce to have Yoshiteru back in Kyoto under his influence. Nagayoshi continued as the real power in Kyoto, with Yoshiteru nothing more than a rubber stamp.
Finally, in 1565, Matsunaga Hisahide invaded Kyoto, which led to a tragic turn of events as Yoshiteru decided to take his own life.
Surrounded by daimyà  who intended only to use the authority of shogun for their own good, Yoshiteru still managed to reaffirm the shà Âguns authority by active diplomacy that extended to every part of Japan. By trying to negotiate a peace between such well-known daimyà  as Takeda Shingen and Uesugi Kenshin, Shimazu Takahisa, à Âtomo Yoshishige, Mà Âri Motonari, and Amago Haruhisa, the shogun's authority was again recognized by various daimyà Â. Lacking resources, Yoshiteru nevertheless saw opportunities to assign his kanji "" on various samurai such as Mà Âri Terumoto to become something close to a godfather. Yoshiteru was well respected for his actions and many researchers credit him as being the last effective shà Âgun to hold the post. Oda Nobunaga and Uesugi Kenshin were among the many daimyà  and samurai who travelled to Kyoto to pay their respects to the shà Âgun.
In 1564, Nagayoshi died of illness and Yoshiteru saw an opportunity to fully reclaim the shà Âguns authority. However, Matsunaga Danjo Hisahide and the three member council of Miyoshi, the Miyoshi Triumvirs, who wanted to rule just as Nagayoshi had, were willing to go to any lengths to remove Yoshiteru from the power and to have Ashikaga Yoshihide as the puppet shà Âgun.
In 1565, Matsunaga Danjo Hisahide's son Matsunaga Hisamichi and Miyoshi Yoshitsugu laid siege against a collection of buildings (that would later become Nijà  Castle) where Yoshiteru lived. With no help arriving in time from the daimyà Âs that could have supported him, Yoshiteru and the few troops under him were overrun by Miyoshi.
In his account of the overthrow of Ashikaga Yoshiteru, Jesuit missionary Father LuÃÂs Fróis mentioned the strong homosexual relationship between Yoshiteru and his squire, Odachidono. According to Father Fróis, the shà Âgun<nowiki/>'s squire, Odachidono:
Three years passed before his cousin Ashikaga Yoshihide became the fourteenth shà Âgun.
Because of his inner strength and the katana skills that he was known to have practiced regularly, Yoshiteru was called the "Kengo shà Âgun" (å£豪å°Âè»Â) and was closer to being a samurai and a warlord than any shà Âgun since Ashikaga Takauji. One of his sword-fighting instructors was Tsukahara Bokuden, the founder of Kashima Shintà Â-ryà «. His governance was highly credited but to have been killed in spite of his efforts completely destroyed what little recognition and authority Yoshiteru built up.
The waka Yoshiteru was said to have left on his death shows the extent of his aspirations compared with the limits of achievements.
There were more than one era name or nengà  in which Yoshiteru was identified as Shogun .
The "Mikazuki Munechika" is another one of JapanâÂÂs Tenka-Goken and is considered the most beautiful of the five blades. This tachi style samurai sword was created Sanjô Munechika and was named for its crescent moon shape (mikazuki). Like all of the Tenka-Goken, the Mikazuki Munechika is one of JapanâÂÂs National Treasures and is currently on display at the Tokyo National Museum.
Over its long history, the Mikazuki Munechika has been owned by several important Japanese families. During the mid-16th century, the Mikazuki Munechika belonged to the Ashikaga family and the sword was used by shogun Ashikaga Yoshiteru to defend himself until he died during an attack on the palace by the Miyoshi family. The sword, along with other Ashikaga treasures, was taken by Miyoshi Masayasu. The Mikazuki Munechika was passed down a few more times before it was owned by the Tokugawa family.