Soe Than Win / AFP - Getty Images

Myanmar opposition leader Aung San Suu Kyi along with other elected members of parliament reads her parliamentary oath at the lower house of parliament during a session in Naypyidaw on Wednesday.

NAYPYITAW, Myanmar -- Opposition leader Aung San Suu Kyi took a historic oath on Wednesday to join a parliamentary system crafted by the generals who locked her away for much of her long struggle against dictatorship, ushering in a dramatic new political era for Myanmar.

The 1991 Nobel Peace Prize winner's debut in a parliament stacked with uniformed soldiers could accelerate reforms that have already included the most sweeping changes in the former British colony since a 1962 military coup, including the release of political prisoners and a loosening of strict media controls.

Suu Kyi's National League for Democracy party will occupy too few seats to have any real power in the ruling-party dominated assembly, however, and there are fears the presence of the opposition lawmakers could simply legitimize the regime without any change.

But the new lawmakers are also likely to bring a level of public debate to the legislative body that has never been seen as they prepare for the next general election in 2015.

The solemn swearing-in ceremony took place in the capital, Naypyitaw, which was built by the former army junta. With white roses in her hair, Suu Kyi stood along with several dozen of her party's lawmakers as the speaker the lower house asked them to read the oath.

Speaking briefly to a mob of reporters afterward, Suu Kyi said her focus will be "to carry out our duties within the parliament as we have been carrying out our duties outside the parliament for the last 20 or so years."

'Cautiously optimistic'
The wildly popular daughter of assassinated independence hero Aung San faces the difficulty of managing the expectations of a nation impatient for change and the hopes of Burmese who see her as a sole beacon for democratic freedom.

Aung San Suu Kyi wins parliament seat in historic Myanmar election

It is unclear how rapidly she can deliver on her ambitious campaign promises, including the overhaul of Myanmar's army-drafted constitution, in a legislature dominated by former members of the military junta who ruled for nearly half a century before ceding to a quasi-civilian government last year.

"Only time will tell," she replied when asked by a Reuters reporter of the day's significance, as she waded through a chaotic throng of reporters on her way to the chamber where she took the oath in a shortened 40-minute session.

Later, she told reporters: "I have always been cautiously optimistic about developments. In politics, you also have to be cautiously optimistic."

Suu Kyi's entry into parliament comes a month after her party's landslide victory in a by-election and two days after backing down in a standoff over the wording of an oath to protect the constitution sworn by all new members of parliament.

The parliamentary session was to have ended on Monday but was extended in part to allow Suu Kyi and fellow members of the National League for Democracy (NLD) to take their seats.

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Entering the chamber, she at first sat down on her own, near the block reserved for serving military men who have a quarter of the seats under the constitution, and seemed relaxed as other lawmakers greeted her.

She then lined up with colleagues to take the oath, including a pledge to uphold a constitution her party wants to change because it gives the military a leading political role.

Asked if she felt awkward working with the military, she replied, "Not at all, I have tremendous goodwill towards the military. It doesn't in any way bother me to sit with them."

Her comments reflect the dramatic scale of change in the former Burma, given the military's past treatment of Suu Kyi, who was first detained by the army in 1989, and then spent 15 of the next 21 years in detention until her release from house arrest in November 2010.

Myanmar house of fear becomes house of hope

Many lawmakers hope Suu Kyi's parliamentary debut will be a catalyst for further reform by the government of President Thein Sein, a former general who has freed hundreds of political prisoners, legalised trade unions and protests, and started a dialogue with ethnic minority rebels.

"Parliament will be stronger because of her good relationship with the international community," said Khin Maung Yi, a lawmaker from the National Democratic Force party. "We parliamentarians have wanted her in the legislature for a long time ... Many laws have to be changed and amended."

Triumph over tragedy
Suu Kyi's story of triumph over tragedy began in 1988 when she left her family life in Britain to take care of her dying mother in Yangon. She soon found herself thrust into politics as nationwide protests erupted against the military, addressing crowds of thousands before her 1989 arrest.

A year later, her NLD won 392 of 485 house seats in a rare election, which the regime ignored.

She was awarded the Nobel Peace Prize in 1991 during the first of three stints under house arrest. Even in her brief periods of freedom, she never left Myanmar, afraid the military would not let her return.

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She refused to leave to be with British husband Michael Aris, an Oxford University academic, when he was diagnosed with prostate cancer. He died in Britain in 1999.

Four years later she survived an assassination attempt in an attack on her motorcade in which dozens of supporters were killed. This led to another spell in detention ordered by a regime that brutally suppressed dissidents.

But as Myanmar changes, so does Suu Kyi. While her decades of defiance were lauded by the world, her decision to join an imperfect political system has also been saluted by the West, which has started relaxing sanctions.

PhotoBlog: Hillary Clinton embraces Suu Kyi following historic talks

And her campaign promise to amend the constitution could put her on a collision course with the army. Last week the military filled its 25 percent house quota with higher-ranking officers in an apparent attempt to boost its parliamentary clout.

But even some of Suu Kyi's fierce rivals in the ruling Union Solidarity and Development Party (USDP) see her presence as a boon for a parliament with limited powers.

"With Suu Kyi on board, parties will be more diverse, with different perspective and opinions," said Kyaw Soe Lay, a lower house USDP lawmaker. "This works in the interest of those in the parliament."

Reuters and The Associated Press contributed to this report.

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