Everything you need to know about North Korean leader Kim Jong Un

— -- As President Donald Trump heads to a historic summit with North Korea, the world is paying close attention to the reclusive state and its secretive ruler, Kim Jong Un.

Kim is the third head of state from his family’s dictatorial dynasty, one of the last inherited absolute monarchies on earth. Yet despite his unrivaled power in North Korea and his command over nuclear weapons and intercontinental ballistic missiles, remarkably little is known about him.

Van Jackson, a scholar on Korean security and an associate professor at the Asia-Pacific Center for Security Studies, told ABC News that North Korea’s secretive nature makes it hard to verify most information coming out of the country.

“Anybody who can answer all your questions with certainty has false confidence. Ask them to prove their answers and they won't be able to,” Jackson said.

In the absence of a reliable official biography, the information publicly available about Kim reflects a “broad consensus understanding” from experts keeping a close eye on the regime, Jackson explained.

Here is what you need to know about the North Korea's reclusive leader:

Early life

State-run media reports Kim was born January 8, 1982, though other reports indicate he may have been born in 1983 or 1984. He is the son of Kim Jong-Il and the grandson of Kim Il Sung, founder of the Democratic People’s Republic of Korea, the official name of the North Korean communist state.

Kim is his father’s third and youngest son, and was born to his father’s third wife, Ko Young Hee. In the 1990s, he attended two private schools in Switzerland, the International School of Berne in Gümligen and the Liebefeld Steinhölzli school near Bern, according to a Vanity Fair profile written by political writer Mark Bowden.

He later returned to the North Korean capital of Pyongyang, where he attended the Kim Il-Sung Military University, the BBC reported.

Dr. Robert Kelly, a professor of political science at Pusan National University in South Korea, said Kim's late estranged half-brother, Kim Jong-Nam, who was murdered on Feb. 13 at the Kuala Lumpur International Airport in Malaysia, was the would-be successor to the throne. Kim Jong-Nam was being groomed for the position until around 2009.

Kelly noted that Kim Jong-Un "lacks the deep institutional and affective relationships with Pyongyang's elite which his father and grandfather had." He "parachuted in late" when his father became ill, according to Kelly.

Rise to power

In 2009, Kim was appointed to the state’s National Defense Commission. The next year, he was promoted to the rank of four-star general and was named vice chairman of the Central Committee of the Workers’ Party of Korea and of the Central Military Commission.

When Kim Jong-Il died in December 2011, Kim Jong-Un was placed at the head of the party, the state and the army within a matter of weeks.

In 2012, state media reported that Kim was married to Ri Sol-Ju. Kim is reportedly a basketball fan. Former NBA star Dennis Rodman has visited North Korea on Kim’s invitation several times. Rodman later told The Guardian that Kim has a daughter named Ju-Ae.

The same year, Kim assumed the title of marshal of the North Korean army, the highest military rank in the country. He briefly disappeared from the public eye in 2014 and later reappeared with a cane.

Kim Jong Un's reign in North Korea

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Most images of North Korean leader Kim Jong Un that are seen by the public are from the country's state-owned Korean Central News Agency. This undated picture released by the KCNA on April 14, 2017, shows him inspecting troops at an undisclosed location in North Korea.

KCNA via KNS/AFP/Getty Images

The U.S. Department of Defense’s 2016 report on North Korea’s military capability described the violent means Kim has used to gain and hold power since assuming control in 2011.

Kim “has solidified his grip on power by embracing the coercive tools used by his father and grandfather. His regime has used force and the threat of force,” combined with suppression of dissenters, to “co-opt” the state military and elites, grow military defense capabilities and challenge the U.S. and its South Korean allies, the report said.

Kelly said Kim seems like a "classic Neronian dictator-figure -- grossly self-indulgent, vicious, prone to self-glorification -- but not stupid or irrational," in a way that might endanger his grip on power.

Nuclear program

According to U.S. Department of Defense, Kim announced a policy of co-developing the country’s economic and nuclear weapons program in April 2013.

Since then, North Korea has continued to develop intermediate and long-range ballistic missiles while staging a series of nuclear tests. Before Kim took control of the state, his father reportedly tested nuclear explosive devices in 2006 and 2009. Kim's regime is believed to have defied international rules six times to test nuclear weapons, most recently in September 2017.

In recent months, the United States has been hoping to secure a deal with North Korea in which Kim would abandon his nuclear program. The White House announced on May 10 that a summit between Trump and Kim would take place June 12 in Singapore.

But diplomatic peace did not last long. Kim threatened to pull back from the summit and criticized the United States with typical, fiery statements. In response, Trump called off the planned summit in an official signed letter.

A week later, Trump announced the summit is back on after a North Korean envoy hand-delivered him a letter from Kim. The highly anticipated meeting is scheduled to be held at the luxury Capella Hotel on Singapore's Sentosa Island.