Profile: Yingluck Shinawatra
Yingluck Shinawatra followed in the footsteps of her more famous brother, Thaksin Shinawatra, when she became Thailand's prime minister.
The former businesswoman became Thailand's first female leader with the Pheu Thai party's victory in the July 2011 general election.
That election win came a year after violent protests on the streets of Bangkok. Since then, under Ms Yingluck, Thailand has enjoyed relative stability.
But a failed attempt to pass a political amnesty bill in November 2013 reignited simmering tensions, fuelling long-standing claims that her government is controlled by her brother, who was ousted from power and lives in self-imposed exile.
Protesters returned to the streets and - so far - show no signs of backing down, leaving Thailand's bitter divisions once against exposed.'Two competencies'
Before the 2011 election, Ms Yingluck, who has two degrees in politics, had never run for office or held a government post.
She had until then pursued a corporate career, formerly as managing director of AIS, the telecommunications firm her brother founded, and managing director of SC Asset Company, a family firm involved in property.
- Born 21 June 1967
- Youngest of nine children; elder brother is former PM Thaksin Shinawatra
- Graduate in political science and business administration, master's degree, Kentucky State University
- Married to businessman Anusorn Amornchat; has one son
- Ex-president of Advanced Info Service (AIS), the country's largest mobile phone operator, before it was sold to Singapore's Temasek Holdings
- Also served as president, SC Asset, a family business
- First woman to run for the country's highest political office
Critics were quick to point out her political inexperience, saying her main qualification appeared to be the fact that she was the youngest sister of Thaksin Shinawatra, the telecommunications billionaire who was ousted as prime minister by the military in 2006 and jailed in absentia for corruption.
They suggested her primary role was to marshal the Thaksin faithful - the mainly poor rural voters who kept him in power - and then serve as his proxy as he governed from overseas exile.
Ms Yingluck performed well on the campaign trail. When she smiled and bent at the knees to exchange a wai - the prayer-like gesture of respect - with a wizened grandmother or weathered farmer, people seemed to warm to her.
In July 2011, the same voters who had put her brother in power backed the Pheu Thai party, which formed a ruling coalition.
Speaking to the BBC after her election win, Ms Yingluck said she planned to work hard.
"My family is a political family plus I have experience in business - I have been running a listed company for 20 years - so I will use the two competencies together to help Thailand to improve, especially in terms of the economy," she said.
After several politically turbulent years in Thailand, people would trust her, she said, as long as the government preserved the rule of law and treated people fairly.
"As long as we solve problems, I hope Thai people will give me a chance to prove myself and show my sincerity," she said.
Three months later, she faced her first challenge as parts of Thailand were hit by severe flooding.
More than 500 people died in the north of the country and a fifth of the capital ended up under water, forcing her government to announce a 100bn baht ($4bn: £2.5bn) recovery plan amid accusations it had been unprepared.
In early 2012, her government approved a compensation fund for victims of recent political unrest - allocating 2bn baht ($63m, £40.8m) to families of the deceased, as well as those who were hurt or ''unfairly detained''.
Ms Yingluck was also seen to establish cordial ties with two key institutions, the royal palace and the military.
But a rice subsidy policy, whereby her government bought rice from farmers at above market rates to boost rural incomes, hit Thailand's rice exports hard.'Rule of democracy'
It was, however, a political amnesty bill that provided the trigger for protests.
Ms Yingluck's government proposed legislation allowing amnesty for those convicted of political violence that took place after the coup that ousted Thaksin Shinawatra, including the mass street protests that paralysed Bangkok in 2010.
It proved unpopular with some of her traditional supporters, who argued it would allow those responsible for the deaths of civilian protesters in 2010 to go free.
But it sparked opposition fury, amid fears the ruling party would use it to allow Thaksin Shinawatra back into Thailand without having to serve his jail term.
And the firm conviction among opposition supporters that Ms Yingluck's government was controlled by her brother caused some to erupt onto the streets in protest.
Ms Yingluck appealed for calm - and allowed the amnesty bill to fail in the Senate. But that did not appease the protesters, who want her government replaced with an unelected "people's council".
The government's decision to call a snap election for 2 February also failed to quell anger. The opposition say they will boycott the polls.
Protesters said they would "shut down" the capital until the government fell. Ms Yingluck reiterated that she was "asking for co-operation" from all sides.
"I am not holding onto my role as a caretaker, but am holding on to the rule of democracy which is owned by the people," she said.
With the polls looking unlikely to deliver a quorum in parliament, it seems Ms Yingluck faces a huge challenge to calm rising tensions.