King Bhumibol Adulyadej certified her appointment with a royal command presented at a ceremony Monday 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.