> China’s leader, Xi Jinping, was the little-known party chief of a city in the coastal province of Fujian during the unrest in 1989. But the PLA’s crushing of that unrest, and the failure of the Soviet army to do the same in Moscow in 1991, leading to the Soviet Union’s collapse, clearly left a deep impression. He has often referred to a critical lesson from it all: the PLA must remain the party’s army and it must be kept under control. It all helps explain Mr Xi’s relentless “anti-corruption” drives among the high command.

Xi was 36 years old in 1989, older than almost all of the current Politburo members. I wouldn’t be surprised if they had very minor roles at that time. Xi’s role was at least partly because he was a princeling - his father was a comrade of Mao Zedong from the old days.

I recommend reading Yashen Huang's "Rise and Fall of the E.A.S.T." [0] - it has a good overview of the cadre during Tiannamen - along with the dated but very comprehensive Tiannamen Papers [1]

[0] - https://yalebooks.yale.edu/book/9780300274912/the-rise-and-f...

[1] - https://www.hachettebookgroup.com/titles/liang-zhang/the-tia...