Gaozong's personal illness, over-affection and trust of Wu led to her wielding a great deal of power in affairs of state until the end of his reign while exerting her influence on him.

Late in 643, Emperor Taizong issued an edict to select beautiful women among good households to serve as Li Zhi's concubines.

After Emperor Taizong's death, all of his concubines who did not bear sons, which included Wu, were housed at Ganye Temple (感業寺) to be Buddhist nuns.

Consort Wu was intelligent and full of machinations, and therefore, when she first returned to the palace, she acted humbly and flattered Empress Wang, who trusted her greatly and recommended her to Emperor Gaozong.

Meanwhile, a faction of officials began to form around Consort Wu, including Li Yifu, Xu, Cui Yixuan (崔義玄), and Yuan Gongyu (袁公瑜).

Meanwhile, Xu Jingzong and Li Yifu, aligned with Empress Wu, and became strong enough to fight for power, began to carry out a campaign of reprisal on her behalf.

In 657, they accused Han Yuan and Lai Ji of plotting treason with Chu Suiliang, who was then serving as the commandant at Gui Prefecture (桂州, roughly modern Guilin, Guangxi).

Asijie, Sijie 思結) Tribe, rebelled against Tang occupation, along with the Western Turkic Khaganate's subject kingdoms Shule (疏勒), Zhujupo (朱俱波), and Yebantuo (謁般陀) (all in modern Kashgar, Xinjiang).

Emperor Gaozong then followed up by commissioning Su, along with Qibi Heli, Liu Boying (劉伯英), and Cheng Mingzhen (程名振), to attack Goguryeo.

They welcomed the Baekje prince Buyeo Pung back from Japan to serve as king, with Juryu (주류, 周留, now Seocheon County, South Chungcheong) as their headquarters.

By 664, Empress Wu, who felt that her power was well established, was extending her influence further in the political arena and increases her controlling behavior over Emperor Gaozong and arbitrarily makes many government decisions.

However, Empress Wu had received information that that was happening, and she emerged to defend herself, when she reached the main palace, she saw the emperor holding a decree and asked seriously: "What is this?"

After the events ended, Empress Wu told Emperor Gaozong: "Your Majesty, you are a wise man who manages the country in an orderly manner, but you are soft-hearted.

Since Empress Wu began to listen to politics in court, she established herself and Gaozong in the same position in front of the civil and military ministers of the Tang dynasty.

In fact, if anyone with a request to make at Court obtains an audience or is allowed to speak, the emperor hears him indeed, but will give no definite answer of "Yes or No", referring him promptly to empress.

The extent of Empress Wu's authority from 665 until the end of Emperor Gaozong, all historians and historical yearbooks state: Hanging the curtain from behind and listening and speaking in government (垂簾聽政, Chuílián tīngzhèng); "Two Saints came to the Court" (二聖臨朝, Er Sheng Lín cháo).The first book: the Later Jin historian Liu Xu, in Old Book of Tang, commented: The Empress of Heaven was at the helm of the country for long years, her power is no different from that of the emperor.

Since the execution of the Shangguan Yi, whenever the emperor went to court, the Empress of Heaven hung a curtain behind the throne (垂簾聽政, Chuílián tīngzhèng), and there was matter of government, great or small, were settled by her, and they were called "Two Saints" (二聖, Er Sheng) inside and outside.

The emperor wanted to issue an edict to make the Empress of Heaven would formally take over the throne of the empire, and Hao Chujun, persuaded him to stop this issue (appoint of regent).The second book: according to Song dynasty historians Ouyang Xiu and Song Qi, in the New Book of Tang: Whenever the emperor was ill, the affairs of the state were left to the empress to decide.

Japan, India, the Persian court in exile, Goguryeo, Baekje, Silla, the Turks, Khotan, the Khmer, and the Umayyad Caliphate all had representatives attending the Feng and Shan sacrifices held by Emperor Gaozong and Empress Wu in 666 at Mount Tai.

[16] In summer 670, the Tibetan Empire captured the 18 prefectures that Tang had established over the Western Regions (Xiyu), and Emperor Gaozong, in response, commissioned Xue Rengui, assisted by Ashina Daozhen (阿史那道真) and Guo Daifeng (郭待封), to attack the Qinghai Lake area, to try to open a second front against the Tibetan Empire as well as to try to restore the territory previously held by Tuyuhun.

However, Guo, who felt himself to be Xue's equal as a general, was displeased at serving as an assistant, and their discord eventually led to a major defeat at the hands of the Tibetan Empire's prime minister Gar Trinring Tsendro.

However, King Munmu formally apologized and offered tribute, Emperor Gaozong and Empress Wu drawal and recalled Kim Immun.

Meanwhile, by this time, even more Emperor Gaozong was continuously suffering from a persistent headache, and he considered making Empress Wu regent, to gain all power.

Both Hao Chujun and Li Yiyan objected strenuously, and Emperor Gaozong did not make her regent, but until the end of his reign, she has decision-making power on most events in the governmental and border matters.

Toward the end of Gaozong's life, Wu began engaging a number of mid-level officials who had literary talent, including Yuan Wanqing (元萬頃), Liu Yizhi, Fan Lübing, Miao Chuke (苗楚客), Zhou Simao (周思茂), and Han Chubin (韓楚賓), to write a number of works on her behalf, including the Biographies of Notable Women (列女傳), Guidelines for Imperial Subjects (臣軌), and New Teachings for Official Staff Members (百僚新誡).

Also in 675, Li Hong the Crown Prince died suddenly—with traditional historians largely attributing his death to poisoning by Empress Wu, due to her anger that he tried to curb her power grab and had shown sympathy to his two older sisters born of Consort Xiao—Princesses Yiyang and Gao'an.

(Buyeo Yung was not able to make any headway in leading his people back to Baekje territory, while Go Jang tried to break away from Tang rule in alliance with the Mohe; when this was discovered, Emperor Gaozong and Empress Wu recalled him to Chang'an and exiled him to Qiong Prefecture.)

Emperor Gaozong was ready to commission an army against Ashina Duzhi and Li Zhefu, but the official Pei Xingjian (裴行儉), who had previously served as secretary general at Xi Prefecture (西州, roughly modern Turfan Prefecture, Xinjiang), opposed—instead proposing that a small detachment be announced to escort the Persian prince Narsieh back to Persia to contend for regal title.

When the officials Xue Yuanchao, Pei Yan, and Gao Zhizhou were put in charge of investigations, they discovered a number of armors in Li Xian's palace.

[18] Imperial physician Qin Minghe (秦鳴鶴), hailing from the West/Daqin (now believed to be from Syria/Eastern Roman Empire)[19] offered a cure of acupuncture and bloodletting, which was applied (and healed the blindness) despite Empress Wu's protests.