Wu Zetian became emperor because she was good at employing people. Wu Zetian was very clever at that time. She knows how to find some very talented people and make them work for herself. Di Renjie was one of the talents appreciated by Wu Zetian, and it was only after this that Di Renjie made great achievements.
At that time, Wu Zetian asked Emperor Renjie to recommend some very special talents to her. Emperor recommended 70-year-old Zhang Jianzhi to Wu Zetian. Wu Zetian saw that Zhang Jianzhi was 70 years old and ignored him. She just promoted him to Sima. But after that, Wu Zetian asked Di Renjie to recommend talents to her. Emperor Renjie refused and firmly told Wu Zetian that Zhang Jian was a very talented person. He should be the prime minister himself, but now he has become a Sima. Such talents should not be buried.
Wu Zetian saw that Di Renjie attached so much importance to Zhang Jian, and named Zhang Jian as Prime Minister. With the reuse of Wu Zetian, Zhang Jianzhi gradually developed his influence in North Korea. When he had enough strength, he joined the DPRK ministers to launch a dragon coup and successfully pulled Wu Zetian off the throne. Originally, Zhang Jianzhi devoted himself to serving the rule of Li Tang, so even though he was in a high position, he was still in Do not forget your initiative mind. Di Renjie recommended him to Wu Zetian because Di Renjie wanted to work for the imperial court in Li Tang, but Wu Zetian was very grateful to him, so he could only choose to continue to work for Wu Zetian. So before Wu Zetian died, she said that she was cheated by Di Renjie. Only then did she find that Di Renjie was on Li Tang's side.