Grandpa in costume watches ancient books video.

I've seen this before. It tells the story of Ming Huidi and Zhu Yunwen in Ming Dynasty. It's called "The Emperor's Journey"

Plot introduction

From childhood to the throne, Zhu Yunwen was a sixteen-year-old boy who loved life, was gentle and kind, and indulged in his own world. Grandfather's cruelty, father's early death and sinister external environment have not hurt his kindness. After Sun Di ascended the throne, he became the focus of power struggle. Although he tried to give up the throne several times, he could not go against God's will. The appearance of Fang Xiaoru just made him realize that the emperor could benefit the people, so he decided to implement the New Deal. Judy, the treacherous prince of Yan, tried to usurp the throne, and war broke out everywhere, causing untold suffering. The benevolent emperor attached great importance to love and affection, so that he missed the opportunity to shovel rape. Bloody court robes, abdicated and fled to the capital. Wen Jian abdicated voluntarily to relieve the suffering of the officers and men and the people. Unexpectedly, his uncle didn't keep his promise and killed someone. Wen Jian was filled with grief and indignation when he saw Fang Xiaoru's tragic death. He wanted to set himself on fire, but fortunately, he was saved by the loyal minister and fled in the cassock left by Mao. Revenge, the road to escape, thinking of the civil and military officials, teachers, relatives and innocent people who died tragically because of him, Wen Jian vowed revenge, so he fled in fear. During this period, he was rescued by a Jianghu friend, and the two eventually became friends of life and death. In the Peach Blossom Garden, Emperor Wen Jian came to Yunnan and went to his uncle Mu Wang, where he was sheltered and anonymous, and waited for a chance to be reset. Enthusiastic cousin gradually fell in love with him, but he fell in love with the gentle and witty actress. Coupled with the separation on the way, it is now a life-and-death friendship for the Royal Guards, and the four of them began a lingering emotional entanglement. Love and hate, the king's daughter fell madly in love with Jianwen Emperor. After learning the true relationship between them, she swallowed her sword and committed suicide. His beloved female singer turned out to be a love of life and death, but life and death are enemies. Finally, the female singer left sadly and died. After the baptism of love and hate, Wen Jian suffered a heavy blow both physically and mentally. After the epiphany, he became a monk. At this time, the plan of revenge was perfect and an army was formed. Although King Mu lost his only daughter, he still fulfilled his promise and wanted to help Emperor Wen Jian to be restored. However, at this time, Emperor Wen Jian had recognized himself and saw through life. Looking back on his 30 years of life, millions of people died for him. Although he is the son of heaven, family, friendship and love are unattainable. On second thought, Wen Jian didn't want to cause another blood shed, so he decided to become a monk and practice all his life.