Former China's Public Security Minister Zhou Yongkang Photo: Reuters
Zhou Yongkang rose through China's state oil industry to become the country's internal security chief and amassed so much power that he brought about his own downfall.
If not for his spectacular downfall, Zhou's life could have been an inspirational rags-to-riches tale. He was born in the eastern industrial city of Wuxi, Jiangsu province in 1942, the son of an eel fisherman in a little-known eastern village. He was the eldest of three boys and the only one to attend university, from which he graduated as an engineer, according to financial news magazine Caixin.
He got his start in the 1970s as a technician for the Liaohe Oil Exploration Bureau in the northeastern province of Liaoning, home to China's third-largest oil field.
By 1996, he had worked his way up to head giant state-owned oil producer China National Petroleum Corporation (CNPC) and went on to become the Communist Party chief in the southwestern province of Sichuan.
He is a central figure in what some analysts have termed the "oil faction" within the Communist Party, a network of influential politicians who have ties with China's powerful and lucrative petroleum industry -- and is sometimes described as "China's Dick Cheney".
In 2002 he ascended to the upper echelons of Chinese leadership, with a slot in the party's 25-member Politburo and the role of minister of public security.
Five years later he stepped up to the elite Politburo Standing Committee (PSC), China's most powerful body, and head of the party's Central Politics and Law Commission (CPLC), responsible for all of China's internal security, including its police, courts, jails and domestic surveillance.
His tenure was marked by the brutal use of force in response to civic unrest, as he oversaw the quelling of riots in Tibet in 2008 and in the Xinjiang Uygur Autonomous Region in 2009.
According to a Chinese finance ministry report, in 2013 the official budget overseen by the CPLC exceeded the national defence budget for the fourth year in a row, with a staggering 769 billion yuan (now $124 billion) spent on domestic security compared with 760 billion yuan (now $123 billion) in military expenditure.
"Maintenance of stability is something very, very vague, and there's a lot of room for corruption," said Joseph Cheng, a professor of political science at the City University of Hong Kong.
"And since there's a lot of room for corruption -- a lot of leeway for spending -- you have a lot of resources to build up your network of ties. That is why he has become so powerful."
That build-up of power and resources -- and a network of proteges and allies eager to establish themselves at the top of the party -- was part of what triggered Zhou's political demise, Cheng added.
Alliance with Bo Xilai
Zhou retired in 2012 as part of a once-a-decade leadership handover, but senior Chinese politicians normally remain significant players even after officially stepping down.
His position as a former PSC member makes him the highest-level official ensnared in the anti-corruption campaign Xi Jinping launched when he took over as party leader, promising to target all levels from high-ranking "tigers" to low-level "flies".
Yet according to experts Zhou's fate was probably sealed by his alliance with Bo Xilai, the openly ambitious, charismatic Communist Party star who last year was sentenced to life in prison for graft.
At least 13 officials connected to Zhou are also under investigation by Chinese authorities, according to announcements in official Chinese media.
They include five current and former top officials in Sichuan; four CNPC officials, including its head and vice president; a vice minister of public security; and three others believed to be right-hand men of Zhou.
Some overseas reports say more than 20 Zhou proteges are currently in detention.
When Zhou stepped down the PSC was cut back from nine members to seven -- with no slot for the country's security chief any more.