As the Shang Dynasty progressed into its later period, its national power gradually declined. Just as the Shang was in decline, a Ji-surnamed tribe named Zhou began to rise west of Qishan Mountain. According to the Records of the Grand Historian, the founding ancestor of the Zhou tribe was Gugong Danfu, who had three sons: Taibo, Yuzhong, and his youngest son Jili. Jili's son was Ji Chang, later known as King Wen of Zhou. Legend has it that auspicious signs appeared at Ji Chang's birth. Gugong Danfu believed Ji Chang would achieve great things in the future, so he intended to pass the throne to Jili so that Chang could eventually succeed. Taibo and Yuzhong, aware of their father's intentions, fled to the Jingman region, where they cut their hair short and tattooed their bodies according to local customs, demonstrating their resolve to yield the throne to their younger brother Jili. Later, Taibo and Yuzhong established the State of Wu in the Lake Tai region.
After Gugong Danfu passed away, Jili succeeded him, taking the title Gongji. Jili not only inherited Gugong's position but also his governance strategies, promoting benevolence and righteousness while actively developing agriculture, which allowed the Zhou tribe to grow rapidly. At that time, the Shang Dynasty ruler was Wen Ding, who adopted a policy of appeasement toward the thriving Zhou tribe, appointing Jili as a pastor, which was a local chieftain. Jili also continuously strengthened political ties with the Shang.
At this time, the Shang Dynasty's power was in decline, as it faced constant invasions from surrounding Rong and Di tribes, yet the Shang repeatedly tolerated and indulged them. Seeing that the Shang ruler did not launch a counterattack, Ji Li unceremoniously waged war against these Rong and Di tribes. He first attacked the Yuwu Rong in the area of present-day Changzhi, Shanxi; the Yuwu Rong were defeated and surrendered, and Ji Li presented the captives and spoils to King Wen Ding of Shang, earning his praise. Wen Ding then entrusted Ji Li with the crucial task of stabilizing the border regions. Consequently, Ji Li next campaigned against the Shihu Rong, who also suffered defeat and surrendered. Within a few years, Ji Li defeated the Yitu Rong, capturing three of their major chieftains and presenting them to Wen Ding. Through these continuous campaigns against border tribes, many feudal lords submitted to Zhou, and Zhou's military strength steadily expanded, making its power increasingly formidable.
The growing strength of the Zhou tribe alarmed King Wen Ding of the Shang Dynasty. To eliminate this threat, Wen Ding suddenly ordered Ji Li to be arrested and soon had him executed.
After Jili died, his son Ji Chang inherited the throne, who later became known as King Wen of Zhou. Upon ascending the throne, King Wen was determined to avenge his father's death at the hands of the Shang Dynasty and worked tirelessly to make Zhou stronger. He continued his grandfather and father's efforts to actively develop agricultural production, while also treating talented individuals with respect, widely recruiting capable people, and promoting those with genuine skills, thus gathering a large number of talents. At the same time, he actively recruited soldiers and horses to enhance military strength.
After Wending killed Jili, he himself died a few years later, and Di Yi ascended the throne, becoming the thirtieth ruler of the Shang Dynasty. Di Yi had just taken control of the realm and had not yet secured his position, so Ji Chang planned to seize this opportunity to attack the Shang and avenge his father. At that time, the Yi tribes between the Yangtze and Huai Rivers had grown strong again, allying with the Mengfang and Linfang tribes to rebel, preparing for a major assault on the Shang.
In this way, Di Yi might face the situation of being attacked from both the east and west simultaneously. To stabilize the overall situation, Di Yi decided to adopt a peace-through-marriage approach, selecting a woman from among his own vassal states to marry Ji Chang, thereby mending the Shang-Zhou relationship that had been broken by his father's killing of Ji Li. The relationship between Zhou and the Shang king was originally one of subordination, and after forming a marital alliance, they became even more interdependent, like lips and teeth. Di Yi hoped that through this, the Shang and Zhou could set aside past grievances and become as close as one family. Ji Chang, assessing the situation and considering that the Shang dynasty had deep-rooted foundations and that the current disparity in strength between the two sides was still significant, believed that the time was not yet ripe to overthrow the Shang. He thought that forming a marriage alliance with the Shang could stabilize the Shang king and buy time to expand his own strength, so he ultimately agreed to the peace-through-marriage.
Emperor Yi personally conducted divination to select an auspicious wedding date, prepared a generous dowry, and appointed Ji Chang to succeed his father Ji Li as the Earl of the West, commanding the western vassal lords. On the wedding day, to show utmost solemnity, the Earl of the West personally went to the northern bank of the Wei River to welcome his bride.
Both the Shang and Zhou sides were delighted, reconciled, and this marriage was widely praised as a beautiful story, historically known as "Di Yi's Marriage of His Daughter." The Book of Changes also contains the "Marriage of the Maiden" hexagram, with the judgment saying, "Marriage of the Maiden: undertaking brings misfortune, nothing is favorable." The hexagram is formed by the trigram Dui below and Zhen above, "indicating the movement of marriage and the image of marrying off a daughter, hence it is called 'Marriage of the Maiden.'"
After stabilizing Queen Zhou, King Yi led the feudal lords to focus on conquering the southeastern Yi tribes, quickly returning victorious and consolidating his rule. King Yi and King Wen of Zhou ascended the throne at roughly the same time. According to oracle bone inscriptions, King Yi reigned for about thirty years, while King Wen reigned for about fifty years, passing away in the later years of King Xin of Shang (the tyrant Zhou). During King Yi's nearly thirty-year reign, there were no further military conflicts between the Shang and Zhou states, showing that King Yi's marriage alliance indeed promoted peace and played a role in ending hostilities.