Yingluck Shinawatra departed the Thai political scene with a dramatic flourish befitting her roller-coaster six-year journey from political novice to premier -- finally falling victim to the army-backed establishment who loathe her family.

According to a senior source in her Pheu Thai party, the 50-year-old ex-premier fled Thailand a few days before the Supreme Court was set to rule whether she was guilty of criminal negligence over a rice subsidy scheme that lavished cash on the Shinawatras' political base.

Her Houdini act, following a cryptic Facebook post late on Thursday, stunned her supporters and media alike who drew a blank on the whereabouts of Thailand's most recognisable politician.

Propelled to power in July 2011 by her family's electoral base in the poor north and northeast, Yingluck was pilloried by foes as a political lightweight armed with little more than a winning smile and a hotline to her elder brother Thaksin Shinawatra -- who once referred to her as his "clone".

But she stepped out of his shadow, displaying a unexpected resilience as protesters besieged her home and opponents clobbered her with a raft of court cases.

"I think that she learned very fast and adapted herself very well... she is very determined to do her duty," Chaturon Chaisang, a veteran politician and former cabinet minister in her toppled government told AFP earlier this week.

"But she might not have understood what was going to happen to her... that she would become the victim of a political game." 

The former businesswoman drew hordes of supporters whenever she toured her electoral heartlands, taking endless selfies and being showered with red roses.

- Tears and smiles -

Her campaigning strategy -- dubbed fighting with smiles -- and her propensity to shed tears in public forged an image far removed from that of the stern junta generals who ousted her from office in a 2014 coup.

In private she wielded authority among her party and entourage, in a country where deference is expected towards wealth and power. 

Her weakness was her elder brother Thaksin, whose deep networks hoisted her to power despite his long absence from Thailand.

The billionaire telecoms tycoon has lived in self-imposed exile since 2008 to avoid jail in Thailand for corruption convictions.

He was ousted as prime minister by an army coup in 2006, which opened a seemingly unbridgeable chasm between his supporters and enemies.

Yingluck's premiership was scuttled in 2014 by a court ruling over a technicality.

Weeks later the army shunted aside the rump of her administration.

For her first two years in office, the outlook seemed very different.

The photogenic former businesswoman charmed many of her critics and for a period maintained the peace across Thailand's bitter political divide.

She reached out to the military and worked to appease political opponents within Thailand's Bangkok-based establishment, which loathes Thaksin and wants to curb the Shinawatras' 13-year influence on Thai politics.

But the shaky truce collapsed in November 2013 after a failed bid to pass an amnesty bill which would have enabled Thaksin's return.

The move outraged government opponents who flooded the streets for months-long protests marked by violence that left dozens dead and hundreds wounded.

Yingluck became the focus of caustic -- and often explicitly sexist -- tirades by protest leaders.

But the mother-of-one refused to joust with her detractors and held off on a violent crackdown. 

She took a leaf out of Thaksin's playbook, launching lavish welfare schemes aimed at the rural poor, including the rice subsidy programme.

The bungled scheme became a lightning rod for anger among protesters and also saw her fall under the glare of anti-graft officials, who are still mulling whether to convict her for negligence -- a charge which carries up to 10 years in prison and a life ban from politics.

Yingluck, who graduated in political science before earning a master's degree in business administration in the United States, spent much of her career working in her brother's empire.

Rising from trainee status, she eventually became president of the mobile telephone unit of Shin Corp., the telecoms giant founded by Thaksin that was at the centre of a tax scandal in 2006.