South Korea elected its first female president, Park Geun-hye, in a close-run contest in December 2012.
Her father President Park Chung-hee, ruled the country for 18 years after seizing power in a coup.
In 1974, at the age of 22, Ms Park became South Korea's first lady when her mother was shot dead by a North Korean assassin's bullet intended for her husband.
In September 2012 Ms Park issued a public apology for human rights abuses committed under her father.
Ms Park, of the Saenuri Party, succeeds Lee Myung-bak, who made good on a pledge to take a tougher line towards North Korea than his predecessor and to strengthen South Korea's alliance with the United States.
In her inauguration speech, she promised to prioritise both national security and economic revitalisation.
To North Korea, she offered a step-by-step trust-building process, but vowed she would "not tolerate any action that threatens the lives of our people and the security of our nation".
Relations with Pyongyang quickly became the first major crisis of her term when the North announced it was restarting the mothballed Yongbyon nuclear complex, pulled its workers out of the Kaesong joint industrial zone and cranked up the bellicose rhetoric in response to US-South Korean military exercises.
The South Korean president holds full executive powers and the premiership is a largely ceremonial post.