Jang Song Thaek had been North Korea's second-most-powerful figure

While hereditary leader Kim Jong Un is the unquestioned ruler of North Korea, until last weekend his uncle, Jang Song Thaek, was thought to be the country's second-most-powerful figure, widely considered Kim's mentor and regent.

But at a high party meeting on Sunday, Jang was yanked out of the assembly by two military guards, his humiliating ouster broadcast on North Korean television. On Friday morning, North Korea's official news agency KCNA announced he had been executed.

Jang, 67, had occupied a privileged and yet precarious spot within the inner circle.

He was the son-in-law of the founder of North Korea, Kim Il Sung, and was married to Kim Il Sung's only daughter, Kim Kyong Hui. She was the younger sister to the former leader, Kim Jong Il, and the aunt of the country's current leader, Kim Jong Un.

Jang's dizzying fall from grace, accompanied by allegations from corruption to womanizing and capped by his arrest at the party meeting Sunday, has suggested to some analysts that the younger Kim is still trying to consolidate the power he inherited from his father two years ago.

Several defense ministers and army chiefs have been replaced as the Workers' Party has asserted control over the military after 17 years of military-first rule under his father, the late leader Kim Jong Il. But Jang's ouster and execution is of a whole different order of importance, and it sends the strongest signal yet to anyone seeking to challenge Kim Jong Un.

Jang had been seen as a regent figure as Kim Jong Un was prepared to succeed his father. He rose in party and military ranks alongside his nephew, often dressed in a trim white general's uniform and standing within arm's length of Kim on field visits and at state events.

Last year, Jang went to China as head of a business delegation to discuss establishing special economic zones. He was also chairman of the State Physical Culture and Sports Guidance Commission, one of Kim Jong Un's pet projects. Kim Jong Un is a basketball fan and famously invited American basketball star Dennis Rodman for a rare official visit to the country.

Last week, South Korea's spy agency reported that Jang might have been dismissed, and said his two closest confidants had been executed.

North Korean state media has not confirmed those executions, but on Friday morning KCNA labeled Jang a "traitor" and announced he had been executed following a special military tribunal held on Thursday.

KCNA said Friday that Jang "committed such hideous crime as attempting to overthrow the state by all sorts of intrigues and despicable methods with a wild ambition to grab the supreme power of our party and state."

Jang's execution raises the question of what will happen to his widow, Kim Kyong Hui. As an offspring of North Korean founder Kim Il Sung, she carries the Kim family bloodlines that underscore their claim to legitimacy.