The mythical ancestor of the house of Zhou was Hou Ji 后稷, the "Lord of Millet", who was later deified as a patron of harvest. His personal name was Qi 弃 and he lived in the plain of Zhouyuan 周原, a place that gave the dynasty its name. The mother of Qi came from the family Tai 邰 (or You Tai 有邰, also written 斄) and was called Jiang Yuan 姜原. She was the main consort of Emperor Di Ku 帝嚳, yet the father of Qi (Hou Ji) is unknown because his mother was impregnated when the stepped on the footprints of a giant. As the fruit of inauspicious origin the baby was "discarded" (qi 弃, i.e. 棄), but it survived miraculously and was thereupon accepted and raised by his mother.
As a child Qi loved to do the work of the peasant population and later became a patron of agriculture. Emperor Yao 堯 made him his Minister of Agriculture (nongshi 農師), invested him as ruler over the territory of Tai and bestowed upon him the title of Hou Ji "Lord of Millet". He was also granted the family name Ji 姬. His descendants continued the work of Hou Ji and cultivated the western region. His descendant Qing Jie 慶節 lived in the small country of Bin 豳 (also written 邠). One of Qing Jie's descendants was Gu Gong Dan Fu 古公亶父 "Father Dan, the Ancient Duke" who revived the remembrance of Hou Ji and his efforts in promoting agriculture. Under his reign the western nomad tribes of the Rong 戎 and Di 狄 continuously attacked the territory of Bin. Dan Fu was of the opinion that it was better to move the whole people than to send the male population into the war, risking their death, and therefore migrated from Bin across the Rivers Qi 漆 and Ju 沮 and the Liangshan Range 梁山 to Qixia 岐下 (or Qishan 岐山), where he and his people settled down. In the new living place he had first constructed a fortified town to shelter the people in case of war. He also created a government with five ministers, namely that of education (situ 司徒), war (sima 司馬), works (sikong 司空), personnel (sishi 司士) and justice (sikou 司寇). Dan Fu is posthumously also called King Tai 周太王 "Great Ancestral King of Zhou".
King Tai had several sons, Tai Bo 太伯, the "Great Earl", Yu Zhong 虞仲 (or Zhong Yong 仲雍) and Ji Li 季歷. When Ji Li's wife Tai Ren 太任 gave birth to Chang 昌, there were auspicious omina, so that King Tai decided to make Ji Li his heir apparent, in the hope that his grandson Chang would become the ruler of Zhou. His older brothers Tai Bo and Yu Zhong were kind enough to accept their father's decision and went into exile among the southern barbarians. Tai Bo's descendants became kings of the state of Wu 吳. Ji Li became a benevolent and kindhearted ruler, reigning in the "way" (dao 道) of his fathers, venerating the old and supporting the young. He was therefore not only respected by his own people, but also by the other regional rulers (zhuhou 諸侯), vassals of the reigning Shang dynasty 商 (17th-11th cent. BCE).
Myths of the transfer of the capital from Bin to Qishan or Hao 鎬 are proved archeologically. Around 1150 BCE, the Zhou moved from the Fen River 汾水 valley in modern Shanxi to the Wei River 渭水 valley in Shaanxi where they settled among the Rong and Di 狄 "barbarians". Although the Zhou people had to carry out permanent fights with their western neighbours, their power gradually grew and finally endangered the existence of the old royal line of the Shang dynasty at Yin 殷 (modern Anyang 安陽, Henan).
Ji Chang 姬昌 inherited the governing style of his father. He attracted a lot of followers like Bo Yi 伯夷, Shu Qi 叔齊, Tai Dian 太顛, Hong Yao 閎夭, Sanyi Sheng 散宜生, Master Yu 鬻子 or Xin Jia 辛甲 who came from far away and served Ji Chang as his ministers. Ji Chang is known as the Earl of the West (Xibo 西伯) or as King Wen 周文王 "the Cultivated", the actual founder of the Zhou dynasty.
The ruler of the Shang empire, King Zhou 紂, suspected the Earl of the West of rebellion and had him encarcerated at Youli 羑里. Hong Yao thereupon presented the king of Shang beautiful women, excellent horses and precious jewels to have his master released. Zhou period historiography praises the Earl of the West for his kindhearted style of rule, which made all vassals of the Shang believe that the Zhou would be the future dynasty that was given the Mandate of Heaven (tianming 天命). After he was set free, Ji Chang began waging war against the nomad tribes of the Rong and also conquered several smaller vassal states in his neighbourhood, like Mixu 密須, Qi 耆, Yu 邘 or Chong 崇. He adopted the title of king (wang) and founded a new capital seat, Fengyi 豐邑. Ji Chang was succeeded by his son Ji Fa 姬發, who is known as King Wu 周武王 "the Martial". During his imprisonement in Youli King Wen had created a method of divination by the sixty-four hexagrams (gua 卦), which is the base of the oracle book Yijing 易經 "Book of Changes".
Shang period oracle bones and a careful examination of the historical texts show that the conquest of the Shang area was mere a result of the general eastern expansion of the Zhou people towards the east and not a the result of a campaign of a "virtuous ruler" against an "evil tyrant".