A rising star is ejected from China's Politburo and faces trial for violations of Communist Party discipline. His wife is in custody, suspected of murdering a British national.

So much for an orderly transition of power.

Just weeks ago, the pending retirement of Chinese president and Communist Party Chief Hu Jintao to the younger generation headed by anointed leader to be Xi Jinping had appeared headed for a quiet repeat of 2002.

That year, Hu took the reins from Jiang Zemin in what was hailed as the first peaceful transition of power in the Chinese Communist Party's history. The party itself believed it had finally come up with a model for orderly and structured leadership handovers.

No longer. The 2002 transition increasingly looks to be the exception.

The ouster of charismatic but controversial former Chongqing party boss Bo Xilai, and the detention of his wife Gu Kailai in connection with the murder of Briton Neil Heywood, conjures images more akin to the sinister and sometimes deadly power politics under Mao Zedong and Deng Xiaoping than to peaceful succession.

Between the two of them, Mao and Deng abandoned five chosen successors who were shoved aside or died in prison, under house arrest or in strange circumstances. Many other senior leaders around them were purged.

Mao ousted his first successor, Liu Shaoqi, during the Cultural Revolution in 1969 and Liu later died in prison. Mao's second, Lin Biao, died in a mysterious plane crash in 1971. He was tried posthumously for treason after what China said was an abortive coup attempt.

According to Party legend, Mao told his third chosen successor, Hua Guofeng, on his deathbed in 1976: With you in charge, my heart is at ease. Hua lasted only a year.

He was deposed in 1977 by Deng, who had been purged twice by Mao before coming back to assume power.

ENDANGERED SPECIES

The revolving door of Communist Party chiefs resumed under Deng, who sacked his own first successor, the reformer Hu Yaobang, in 1987 for being too soft on Western ideas.

Hu Yaobang's death in April 1989 sparked spontaneous memorials in Tiananmen Square that turned into the student-led democracy protests that were the undoing of Deng's second successor, Zhao Ziyang. Zhao was removed in May 1989 for sympathising with the student protests that were crushed with deadly force later by the People's Liberation Army.

A political joke that circulated around Beijing in late 1989 put Deng in a car with two other senior leaders when a cow blocked the road. One leader warned they would declare martial law. The cow didn't budge. The other said they'd send in the army. The stubborn bovine stood fast.

It was only when Deng whispered in its ear that he would appoint it as Communist Party chief that the cow fled in fright.

Deng's last pick, Jiang Zemin, defied the odds. With remarkable staying power, he ousted his own rivals and served as party chief over the next decade until handing over to Hu Jintao in 2002 to mark the first peaceful transition.

Bo Xilai was not a candidate for one of China's top two posts. But the former commerce minister was actively campaigning for one of nine seats on the next Politburo Standing Committee, the elite body that will run China under Hu's anointed successor Xi Jinping after a Party Congress late this year.

The bizarre drama surrounding Bo's removal, triggered when his own police chief, Wang Lijun, fled into the U.S. consulate in Chengdu apparently seeking asylum, hearkens back to power politics of old.

While the Party maintains a veil of secrecy and decides its top personnel moves - including Bo's fate - behind closed doors, his purge has sparked tensions with some conservative leftists and other supporters and upset with the disruption of what once appeared to be another routine transition.

In a sign of how fraught the leadership transition has become, the party mouthpiece, the People's Daily, issued a call for unity alongside Tuesday's reports of Bo's removal from the Politburo and broader Party Central Committee.

We must conscientiously unify our thinking around the spirit of the central leadership, and closely unite around the party's central leadership with Comrade Hu Jintao as general secretary, it said.

If the tensions sparked by Bo's downfall are any sign, holding Party unity will prove a challenge.

(Editing by Don Durfee and Jonathan Thatcher)