China's most senior general is under investigation, China's defence ministry said on Saturday, in the highest-profile purge to date of senior military leadership just as Beijing modernises its forces and tries to further project its might.

Zhang Youxia serves as second-in-command under President Xi Jinping as vice-chairman of the Central Military Commission - the supreme command body - and has long been seen as Xi's closest military ally.

The ministry said Zhang and Liu Zhenli, chief of staff of the CMC's Joint Staff Department, were under investigation for suspected serious violations of discipline and law.

Zhang is also a member of the elite Politburo of the ruling Communist Party and is one of just a few leading officers with combat experience.

Sweeping crackdown targets military

The military was one of the main targets of a broad corruption crackdown ordered by Xi in 2012. That drive reached the upper echelons of the People's Liberation Army in 2023 when the elite Rocket Force was targeted.

Zhang's removal is the second of a sitting general on the Central Military Commission since the 1966-76 Cultural Revolution. He has not been seen in public since November 20, when he held talks with Russia's defence minister in Moscow.

Foreign diplomats and security analysts are watching developments closely, given Zhang's closeness to Xi and the importance of the commission's work in terms of command as well as the PLA's ongoing military modernisation and posture.

China is flexing might

While China has not fought a war in decades, it is taking an increasingly muscular line in the disputed East China Sea and South China Sea, as well as over the self-ruled island of Taiwan, which is claimed by China. Beijing staged the largest military exercises to date around Taiwan late last year.

Singapore-based China security scholar James Char said the military's daily operations could carry on as normal despite the purges but the targeting of Zhang showed Xi was reacting to criticism that the crackdown had been too selective.

"Xi has been tapping on second-line PLA officers to fill those roles vacated by their predecessors – on an interim basis in most cases," said Char, a scholar at the S. Rajaratnam School of International Studies.

"China’s military modernizers will continue to push for the two goals Xi has set for the PLA – namely, 2035 to basically complete its modernisation and 2049 to become a world-class armed forces."

Zhang is the second vice chair of the CMC to fall from grace in recent months. Former CMC vice chair He Weidong was expelled from the party and PLA in October last year for corruption. He was replaced by Zhang Shengmin.

Eight top generals were expelled from the Communist Party on graft charges in October 2025, including He Weidong.

Two former defence ministers were also purged from the ruling party in recent years for corruption. The crackdown is slowing procurement of advanced weaponry and hitting the revenues of some of China's biggest defence firms.

Children of civil war veterans

Both Xi and Zhang are from the northwestern province of Shaanxi and are the children of former senior officials who fought together in the 1940s civil war.

Born in Beijing, Zhang joined the army in 1968, rising through the ranks and joining the military commission in late 2012 as the PLA's modernisation drive gathered pace.

A Pentagon profile of Zhang in late 2023 noted that Zhang had been expected to retire in 2022, aged 72, given usual military practice.

"However, Zhang's retention on the CMC for a third term probably reflects Xi's desire to keep a close and experienced ally as his top military adviser," the profile said, contained within the Pentagon's annual report on China's military that year.

He fought Vietnam in a brief but bloody border war in 1979 that China launched in punishment for Vietnam invading Cambodia the previous year and ousting the Beijing-backed Khmer Rouge.

Zhang was 26 when he was sent to the front lines to fight the Vietnamese and was quickly promoted, according to state media. He also fought in another border clash with Vietnam in 1984 as the conflict rumbled on.

"During the battle, whether attacking or defending, Zhang Youxia performed excellently," the official China Youth Daily wrote in a 2017 piece entitled, "These Chinese generals have killed the enemy on the battlefield".

Some China scholars have noted that Zhang emerged from the conflict an avowed moderniser in terms of military tactics, weapons and the need for a better trained force.