In the first year of Shenlong (705), the final year of Wu Zetian's reign—the founding ruler of Wu Zhou, which had replaced Tang with Zhou, and the only legitimate Empress in Shenzhou's history.
Likewise... she was one of the oldest rulers to ascend the throne, at sixty-seven, and one of the longest-lived, reaching eighty-two. She was known alongside Empress Lü of the Han Dynasty as "Lü-Wu."
That year, the eighty-two-year-old Wu Zetian fell gravely ill.
In the first month, Chancellor Zhang Jianzhi, Right Imperial Forest Army Great General Li Duozuo, Left Might Guard general Xue Sixing, and others launched the Shenlong Coup. They suddenly led more than five hundred Imperial Forest Army soldiers through Xuanwu Gate and killed Zhang Yizhi and Zhang Changzong in Yingxian Palace.
That day, Prince Xiang Li Dan also led the Southern Palace Imperial Guards to strengthen security and coordinate the operation. Left with no choice, Wu Zetian first ordered the Crown Prince to oversee the state, then abdicated the following day. One day later, Li Xian returned to the throne as Emperor and granted a general amnesty.
During Li Xian's reign, he restored the old Tang Dynasty institutions, exempted taxes and levies, established the Ten Circuit Inspectors and Xiouwen Hall Scholars, developed economic and cultural exchanges with Tubo, and adopted a marriage alliance policy. He married Princess Jincheng to Tubo's tsenpo, Chizhudan, ensuring stability along the border regions.
Yet... Emperor Zhongzong of Tang, Li Xian, ruled twice, but his combined reign lasted only five and a half years. In the fourth year of Jinglong (710), on the Renwu day of the sixth month, he was poisoned to death at the age of fifty-five. His posthumous title was Emperor Dahe Dasheng Dazhao Xiao.
At this time, although Great Tang remained powerful, it was already far inferior