Kim Jong Un, who vaulted into the leadership role with the death of his father, Kim Jong Il, made his public debut as anointed successor only 15 months ago. Since then, the whirlwind political campaign has barreled ahead — but perhaps not fast enough to mask the air of uncertainty felt in the streets of Pyongyang, the North Korean capital.

The late Kim Jong Il had 20 years of preparation at the side of his father, North Korean founder Kim Il Sung, who died in 1994. Experts say that because Kim Jong Un doesn’t have that kind of experience, the youngest member of the political dynasty will need the brains and political brawn of his father’s closest confidants before formally taking power.

"Kim Jong Il was in a frantic race against time," said Jonathan Pollack, a North Korea expert at the Brookings Institution in Washington, "and he lost."

Analysts say two close, trusted family members and political power brokers have emerged as Kim Jong Un’s main protectors: paternal aunt Kim Kyong Hui and her husband, Jang Song Thaek, who have risen to the top of North Korea’s political and military elite since the succession campaign began two years ago.

Both 65, they also have the weight of seniority so important in a society that places a premium on age and alliances.

A last photograph of Kim Jong Il released Saturday by the official Korean Central News Agency shows just how important the aunt and uncle are to Kim Jong Un. In it, Kim Jong Il is descending on an escalator at a Pyongyang supermarket with a group behind him that includes his sister, Kim Kyong Hui, and her husband, Jang Song Thaek, on steps below and above their nephew, the heir.

Making his first public appearance Tuesday following his father’s death, Kim Jong Un approached and bowed deeply before the bier in a memorial palace, the picture of vigor and filial piety. Lined up alongside members of the elder Kim’s inner circle, he was the youthful exception among officials in their 60s, 70s and 80s who were his father’s closest confidants.

Kim, whose age has never been revealed in North Korea, is 27 years old, according to a U.S. official in Washington. Among Kim Jong Il’s three sons, he is most like his father in manner and personality.

"Kim Jong Il picked the apple that didn’t fall far from the tree," the official said, speaking on condition of anonymity in exchange for the details. "He didn’t select a successor who he believed would radically depart from his vision for North Korea."

When Kim Jong Un will formally assume power remains unclear.

Official mourning periods can last for months or even years in North Korea. Kim Jong Il observed a three-year period of mourning after the death of his father before formally assuming leadership, said John Delury, an assistant professor at Yonsei University’s Graduate School of International Studies in South Korea.

He said Kim Jong Un may take a back seat to a group of regents during an extended mourning period.

"The question will be: If he does — again in accordance with traditional mourning and his young age — take a little bit of a back seat, even for a couple years as he establishes himself, then it’s going to be very difficult to figure out what’s the balance of control between Kim Jong Un and these other more senior, more experienced figures."

John Park of the U.S. Institute for Peace calls the aunt and uncle "key pillars" for Kim as he looks to establish his leadership. But he questions whether their power — derived from their personal association with Kim Jong Il — will endure now that he’s gone.

"Jang is clearly someone whose major task on behalf of the Kim family is to guide and shepherd Kim Jong Un, and to insulate and protect him … to help him ward off assaults on the authority of the family," said former U.S. special envoy for North Korea Stephen Bosworth.

An important factor in his favor is that North Korea has only known rule by the Kims, and military and party leaders likely view a successful transition as key to their survival.

"The North Korean regime is in a classic, ‘we all hang together or we all hang separately’ kind of mode," Bosworth said. "There’s a great imperative for cohesion."

Kim Jong Il played rival groups off one another, but everyone knew their position relied on him.

"The key question is whether Kim Jong Un can achieve that, even in coordination with his regent aunt and uncle," Park said.

Here is a look at key members of the inner circle in North Korea:

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KIM KYONG HUI

Kim is the late leader’s younger sister. She kept a low profile for decades until 2009, when she began appearing with her brother during "on-the-spot guidance" trips nationwide. Now considered a top political official who has shot up in the ranks in two years, she is expected to play a caretaker role with her nephew.

She serves as director of the light industry department of the ruling Workers’ Party’s Central Committee, a position that has gained significance since North Korea made the industry sector a priority in 2009. She was also appointed to the Political Bureau last year and, like her nephew, was made a general in the Korean People’s Army.

Kim is said to have a fiery temperament but suffers from ill health, according to North Korea observers based in Seoul.

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JANG SONG THAEK

Kim Kyong Hui’s husband is a Soviet-trained technocrat who was a rising star until he was demoted in early 2004, seen as a warning from his brother-in-law against cultivating too much influence.

Jang was brought back into the fold in 2006, and he has been gaining influence since then. He heads the party’s administrative department, and more importantly oversees the intelligence agency and other military-related institutions, according to the Sejong Research Institute, a security think tank in South Korea.

In June 2009, he was made a vice chairman of the powerful National Defense Commission and is an alternate member of the Political Bureau. He has strong ties to the military, with two brothers having served in high-level military posts, according to analysts.

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Other key members:

— Kim Yong Nam, president of Presidium of North Korea’s parliament, often represents the country and is considered a nominal head of state. He is a member of the party’s Central Committee.

— Ri Yong Ho, vice marshal and chief of the General Staff of the Korean People’s Army, promoted to vice chairman of the party’s Central Military Commission last year and a member of the Presidium of the Political Bureau. Ri was close to Kim Jong Il and is said to have strong ties with Jang.

— Choe Yong Rim, promoted to premier last year. His family is said to have long-standing ties with the Kim family. His daughter, Choe Son Hui, is a department director at the Ministry of Foreign Affairs. Choe, though in his 80s, has been making an increasing number of "on-the-spot guidance" trips this year, similar to those made by Kim Jong Il.

Concerns about the post-Kim Jong Il era began mounting in 2008 when he disappeared from the public eye after suffering a stroke. North Korea began closing ranks in 2009 during the early stages of a movement to begin installing a successor.

The party’s Political Bureau, which had atrophied during much of Kim Jong Il’s "military first" rule, was restocked with loyal, mostly older cadres in 2010. The emphasis on the Kim family’s lineage and legitimacy to lead North Korea was promoted by state media.

In taking the dynasty into a third generation, Kim Jong Un faces the challenge of convincing his people and the outside world that he has the clout and connections to make up for his youth and inexperience.

He will be dealing with poverty, hunger, isolation and questions about the military’s support, but "he has no profile in the party, no profile in the military," said Victor Cha, a senior adviser at the Center for Strategic and International Studies. "Things could really come apart."

"The question is whether these deeply personalized associations of Kim Jong Il persist with the young general," Pollack said.

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Lee is Korea bureau chief, based in Seoul. Pennington reported from Washington. Associated Press writers Kimberly Dozier in Washington, Alexa Olesen and Charles Hutzler in Beijing, and Jiyoung Won in Seoul, South Korea, also contributed to this report. Follow Jean H. Lee on Twitter at twitter.com/newsjean.