Yingluck Shinawatra, the sister of an ousted Thai leader, vowed Monday to work for national reconciliation as she formally became the country's first female prime minister.
King Bhumibol Adulyadej certified her appointment as the country's 28th prime minister with a royal command presented at a ceremony at her Pheu Thai party headquarters.
Yingluck's brother, former Prime Minister Thaksin Shinawatra, was removed by a 2006 military coup after being accused of corruption and disrespect for the monarchy. His ouster set off a sometimes violent struggle for power between his supporters and opponents that continues to leave the country polarized.
The 44-year-old Yingluck attended the ceremony with her husband and 9-year-old son. After a parliamentary officer read the royal command, she prostrated herself before the king's portrait.
In a brief speech, Yingluck emphasized her loyalty and gratitude toward the monarchy, in remarks clearly meant to reassure critics who felt Thaksin attempted to usurp the crown's authority. With 83-year-old King Bhumibol in shaky health, there is uncertainly about the future of the monarchy.
Yingluck broadly addressed another contentious issue, the political divide that left Bangkok a battleground for two months last year as anti-government demonstrations by Thaksin supporters deteriorated into violence, leaving 91 people dead and more than 1,400 injured.
Thaksin's opponents staged their own disruptive protests in 2008, taking over the prime minister's offices for three months and occupying Bangkok's two airports for a week.
Yingluck vowed to use her "knowledge, ability and wisdom" to "lead our country to peace and reconciliation."
In July 3 elections, her party gained a 265-seat absolute majority in the 500-member lower house of Parliament, and she has hammered together a six-party coalition holding 300 seats in all.
Pheu Thai spokesman Prompong Nopparit said her Cabinet lineup will be forwarded for the king's approval as early as Tuesday.