He was born the son of Satake Yoshiaki, a warring-states lord of Hitachi Province, now Ibaraki Prefecture. The Satake were a distinguished Minamoto family dating back to the Heian period. His mother came from the Iwaki of Mutsu, and the "shige" in his name seems to have come from his maternal grandfather Iwaki Shigetaka. He grew up in a land surrounded by powerful lords.
When his father Yoshiaki retired, he succeeded as the eighteenth head of the Satake. For a while, though, his father held real power. Two years later he cooperated with Uesugi Kenshin of Echigo to drive Oda Ujiharu from Oda Castle, and thereafter, strengthening his ties with Kenshin, he fought battle after battle aiming to unify Hitachi.
He defeated his archrival Oda Ujiharu at Tehaizaka and took Oda Castle. Yoshishige went on to bring the Shirakawa Yūki and Iwaki under him and made peace with the Nasu of Shimotsuke, expanding his power. Brave tales, such as felling seven enemies in an instant on the battlefield, later earned him the name "Demon Yoshishige" (accounts vary).
His rapid expansion alarmed neighboring lords, and attacked by both the Hōjō and the Ashina, he found himself in a difficult position. Yoshishige allied with the Yūki and Utsunomiya through marriages and cultivated friendship with Hashiba Hideyoshi far away in the Kinai. This year he formed an alliance with Ashina Moritaka of Aizu, building a front against the Hōjō.
While pressed by a great Hōjō army into an unfavorable peace, to the north a struggle with Date Masamune began. Yoshishige formed an allied army with the Ashina and others and gained the upper hand against Masamune's forces in the Battle of Hitotoribashi, but withdrew because of unrest in Hitachi during his absence. Masamune is later said to have called it the greatest battle of his life.
To the Ashina, whose heirs had died one after another, he sent his second son Yoshihiro as adopted heir. The Date, who had hoped to place Masamune's younger brother in the Ashina house, strongly objected. In the Kōriyama battle the next year he faced Masamune with a large army, but the allied forces were not united, and they made peace without a decision.
Yoshihiro suffered a crushing defeat by Masamune at Suriagehara, and the lords of southern Mutsu went over to the Date one after another. Caught between the Hōjō to the south and the Date to the north, the Satake faced destruction. This year Yoshishige handed headship to his eldest son Yoshinobu and retired, though he kept real power.
When Toyotomi Hideyoshi, with whom he had long been on good terms, began the Odawara campaign, Yoshishige hurried to Odawara with Yoshinobu. This decision paid off, and Hideyoshi recognized his rule over Hitachi with 540,000 koku. The Satake, who had been in crisis, managed to turn the situation around at a stroke.
With Hideyoshi's backing, he removed one after another the forces in Hitachi that would not submit. Through a scheme he also destroyed the lords of the "Thirty-Three Houses of the South" who held residences in Kashima and Namegata districts, at last unifying the whole of Hitachi. Afterwards he left government to Yoshinobu and lived at Ōta Castle, called "Lord of the North Castle".
At the Battle of Sekigahara, while Yoshinobu, a friend of Ishida Mitsunari, wanted to join the Western army, Yoshishige, who read the trend of the times, urged siding with Tokugawa Ieyasu's Eastern army, and father and son clashed. After the war the Satake were blamed for their ambiguous stance, and two years later their domain was moved to Kubota in Dewa.
After moving to Dewa he lived at Rokugō Castle, developing the town and watching over the south of the domain against uprisings opposed to the Satake. This year he died after falling from his horse while hunting. He was known as a lover of swords, and stories tell of his unpretentious character, sleeping without a mattress even in the cold north.
Uesugi KenshinToyotomi HideyoshiTokugawa IeyasuIshida MitsunariDate Masamune
Mogami YoshiakiOichiSanada MasayukiAsano NagamasaOda Nagamasu (Urakusai)Honda TadakatsuNene (Kōdai-in)Sakakibara Yasumasa
People of the Sengoku/Azuchi-Momoyama period ・ People by period
Based on facts found in textbooks and biographies. Uncertain points are marked as such.