South Korean President Moon Jae-in is the son of North Korean refugees. Tomorrow he will meet the third supreme leader in the North Korean Kim dynasty, Kim Jong-un, face to face for the first time.

North and South Korea are technically still at war. They have been ever since a truce brought an end to the Korean war in 1953. However, in the more than half a century since, there have been a number of efforts to remove the cloud of conflict that continues to hang over the peninsula.

RTÉ’s Laura Fletcher takes a look at the long standing history of tension between the two Koreas and their allies, and previous attempts at peace.

Korea North and South

The division of Korea took place after World War II with the end of Japan's colonial rule.

Soviet Union troops occupied the North, and United States troops occupied the South, until 1948 when two ideologically opposite countries were established on either side of the border: The Republic of Korea (South Korea) and the Democratic People's Republic of Korea (North Korea) under the leadership of Soviet trained Kim Il-sung.

The Korean War

In 1950 South Korea declared independence, a move that was quickly followed by a North Korean invasion, and the beginning of the Korean War.

North Korea was supported by the Soviet Union and Chinese forces fought on its side. A United Nations Command force, largely made up of US troops, fought alongside the South Koreans.

After three years of fighting and more two million deaths, an armistice was signed and a Demilitarised Zone was established along the border.

The 1972 Joint Statement

In 1971 Red Cross societies on both sides of the border began a series of talks, initiated to help reunite families separated by the conflict.

While little progress was made on that issue, these talks ultimately led to secret political negotiations and on 4 July 1972 North and South Korea issued a Joint Statement on the principals for peaceful reunification. However the thaw in relations did not last and North Korea suspended talks in August the following year.

The 80s: Talks and ‘Team Spirit’

1984 saw renewed efforts at talks between the Koreas, and again the local Red Cross societies were pivotal. It was during this time that North Korea signed the Nuclear Non-Proliferation Treaty.

Talks foundered as tensions flared over the US/South Korean joint military exercise ‘Team Spirit’ in January 1986, but not before the first reunion of families separated by the Korean War took place in September 1985.

There was more progress in 1988, when inter-Korean economic cooperation began.

The 90s: Nuclear Agreements

The 90s heralded the end of the Cold War and with it the removal of all US nuclear weapons from South Korea in 1991.

Already in September the previous year, high-level North/South talks had been held in Seoul.

In 1991 the Koreas signed the Agreement on Reconciliation, Non-Aggression, Exchanges and Cooperation, and the following year they signed the Joint Declaration on the Denuclearisation of the Korean Peninsula.

However, in 1993 North Korea was accused of violating the Nuclear Non-Proliferation Treaty and in turn Pyongyang threatened to withdraw from it.

In July the next year North Korean Leader Kim Il-sung died. His son Kim Jong-il succeeded him.

Around this time the US held a series of talks with North Korea which resulted in an "Agreed Framework" being reached in October 1994.

It required Pyongyang to freeze and eventually eliminate its nuclear facilities, in exchange for fuel and two new proliferation-resistant nuclear reactors.

In August 1998 North Korea fired a long-range rocket over Japan, well beyond its previously known capabilities.

It was also in 1998 that South Korean President Kim Dae-jung unveiled his "Sunshine Policy" of offering economic and humanitarian aid to North Korea, something which earned him a Nobel peace prize.

Optimism in a new millennium

In June 2000 the first ever inter-Korean summit saw Kim Jong-il and Kim Dae-jung meet in Pyongyang and sign a peace accord. This lead to border liaison offices being re-opened in the Demilitarised Zone in August.

South Korea gave an amnesty to more than 3,500 North Korean prisoners and a further family reunifications took place, while in September the two Koreas marched under a Korean Unification Flag at the Sydney Olympics.

In October of that year US/North Korean efforts moved up a gear too.

US President Bill Clinton met a senior North Korean military official who had travelled to Washington. Jo Myong-rok was second in command only to Kim Jong-il on North Korea’s National Defence Commission.

This unusual goodwill mission was followed by US Secretary of State Madeline Albright’s trip to Pyongyang to meet Kim Jong-il.

"Axis of Evil"

In January 2002 in a post-9/11 America, President George W Bush named North Korea, along with Iran and Iraq as part of an "axis of evil" for building "weapons of mass destruction."

In 2003 North Korea withdrew from the Nuclear Non-Proliferation Treaty and 1992’s Joint Declaration on the Denuclearisation of the Korean Peninsula.

The first Six-Party talks were held in Beijing between North Korea, South Korea, Japan, Russia, China and the US to try and reach some kind of agreement on the nuclear issue.

There were six rounds of Six-Party talks between 2003 and 2009, when North Korea pulled out.

In October 2006 North Korea announced that it had conducted its first nuclear weapons test. The UN responded with economic and commercial sanctions.

Sunshine fades

In October 2007 a second inter-Korean summit took place, again in Pyongyang, during which the South Korean President Roh Moo-hyun and North Korean leader Kim Jong-il signed an eight-point peace agreement.

But in 2008 relations cooled as the newly elected South Korean President Lee Myung-bak cut off aid to North Korea bringing an end to the South’s Sunshine Policy.

In March 2010 South Korea cuts all trade ties with the North after it said a North Korean torpedo sank its naval ship, Cheonan, with the loss of 46 lives.

Kim Jong-un’s nuclear push

The death of Kim Jong-il in 2011 saw his son Kim Jong-un succeed him.

Under his rule North Korea accelerated its banned nuclear and ballistic missile programmes, testing more missiles than under the two previous leaders combined.

While North Korea’s claim that it had tested a hydrogen bomb in January 2016 was met with international scepticism, analysts were less sure when in September 2017 it again said it had tested a H-bomb.

The tremor from that blast was felt in China, 400km away, and nuclear weapons specialists put the blast yield at about 100 kilotons. That’s roughly 10 times more powerful than any of North Korea’s previous nuclear bombs tests.

2017 also saw North Korea launch 23 missiles, including its first intercontinental missiles, which it said could reach anywhere on the US mainland.

Both US and South Korean authorities said they believed Pyongyang would be able to pair their nuclear and missile capabilities in 2018.

As North Korea ramped up its weapons tests, US President Donald Trump ramped up his rhetoric.

Speaking to the United Nations in September 2017, while addressing the UN General Assembly President Trump called Kim Jong-un a "rocketman…on a suicide mission" and warned the United States would "totally destroy North Korea" if it had to defend itself or its allies.

Kim Jong-un responded with threats and insults of his own calling Donald Trump a "mentally deranged US dotard", saying he would "pay dearly" for his threats.

It was against this backdrop of increasing tension that South Korea’s New President Moon Jae-in was sworn in. During the ceremony he spoke of "peace on the Korean Peninsula" and promised "I will do everything that I can do."

The Peace Olympics

The New Year rang in new opportunities for talks.

Kim Jong-un used his New Year’s Day address to strike a conciliatory tone with South Korea, saying that "North and South must work together … to find peace and stability."

He also opened the door to participating in February’s Winter Olympics in South Korea, saying talks should begin "as soon as possible."

Those talks yielded positive results.

North Korean athletes participated in the Games alongside their southern neighbours under a Korean Unification Flag. The opening ceremony was attended by Kim Jong-un’s sister Kim Yo-jong, the first member of the Kim family to step onto South Korean soil since the Korean War.

She invited President Moon Jae-in to North Korea, laying the foundation for Friday’s summit, while a senior North Korean official who attended the closing ceremony, Kim Yong-chol, said the North was open to dialogue with the United States.

In March, South Korea’s National Security Advisor, Chung Eui-yong, held talks with Kim Jong-un in Pyongyang.

He returned saying that North Korea was willing to give up its nuclear weapons if, as he put it, "the military threat to North Korea was resolved."

Two days later US President Donald Trump confirmed that he had accepted an invite to meet Kim Jong-un.

This will be the first time a sitting US President will meet a North Korean leader. Details are still being thrashed out, but they are expected to meet by early June.

Earlier this month, North Korea announced that it was suspending nuclear and long range missile tests, saying it no longer needed to carry out such tests.

Tomorrow, for a third time, the leaders of the two Koreas will meet.

This time though, it will take place on the Southern part of the Demilitarised Zone.

There are three items reported to be on the agenda: denuclearisation, creating a peace regime, and improving inter-Korean ties, with announcements already expected on the latter two.

Progress on denuclearisation may come more slowly, if at all.