The Lockerbie Bombing was the biggest terrorist attack against the United States before 9/11 – and it occurred over Scottish territory.

Questions around the plane bombing, and justice for the 270 people who died as a result of the attack, have continued for the near-four decades since it occurred.

The complicated case has sparked numerous documentaries, and has been recreated in a new Sky Original series, led by Colin Firth.

Firth plays Jim Swire, whose daughter, Flora, was one of those who lost their lives in the attack. The series will follow his quest for justice, and his fight for humanity amid one of the most horrific terrorist incidents in recorded history.

Here’s the full timeline of what happened on the day, what happened since, and what’s to come.

38 minutes after take-off, Pan Am Flight 103, on transit from London to New York, explodes at 31,000 feet over Lockerbie, Scotland. All 259 people on board the flight – 243 passengers and 16 crew members – as well as 11 people on the ground die as a result of the explosion. There were victims from 21 different countries.

Abdelbaset al-Megrahi and Al Amin Khalifa Fhimah, Libyan Nationalists and suspected Libyan intelligence agents, are indicted on 270 counts of murder, as well as conspiracy to murder and violations of Britain’s 1982 Aviation Security Act.

Libya announces their intent to try the pair in their own courts.

After Libya refuses to hand over the suspects for a Scottish trial, the UN Security Council imposes bans on air travel and arms sales with the country. By the end of the year, this is extended to freeze Libyan assets in foreign banks, as well as the import of spare parts for the oil industry.

Relatives of those who died on Pan Am Flight 103 launch a civil case against Pan American World Airways.

Pan Am is found guilty of wilful misconduct that allowed the bombing to take place by a Federal District Court. This allows the relatives to sue the company for damages.

A new agreement is reached to put the suspects on trial on neutral territory in the Netherlands, but under Scottish law.

Abdelbaset al-Megrahi and Al Amin Khalifa Fhimah are taken into Dutch custody and formally charged with the bombing. The UN Security Council’s sanctions are temporarily suspended.

The trial begins at Camp Zeist, a former US military base in Utrecht, The Netherlands. A school on the grounds was turned into a court for the case, and was a special sitting of the High Court of Justiciary set up under Scottish law. Both plead not guilty to the crimes they are accused of.

During the trial, conspiracy charges against the pair are dropped, with only the murder charges remaining.

Abdelbaset al-Megrahi is found guilty at trial, with the judges recommending a minimum of 20 years for the vastness of the crime. Al Amin Khalifa Fhimah was found not guilty, and was released to return home.

al-Megrahi loses his first appeal against his conviction, and is sent to HMP Barlinnie in Glasgow.

After negotiations in London, Lockerbie bombing victims reach a compensation agreement via their lawyers with the country of Libya. Officials clear a £1.7 billion fund to be split between the families of those who died on the flight. The country officially accepts responsibility for the bombing.

al-Megrahi is officially told he must serve a minimum of 27 years in prison for the bombing.

As part of a new peace agreement, Colonel Gaddafi agrees to dismantle Libya’s nuclear programme, destroying all chemical, nuclear, and biological weapons.

The Scottish Criminal Cases Review Commission recommends al-Megrahi get a second appeal against his conviction.

al-Megrahi’s representatives announce he has been diagnosed with advanced prostate cancer.

Jim Swire, whose daughter Flora was killed in the bombing, calls for al-Megrahi to be released, citing “common humanity” and criticising the length of his appeals process.

It is ruled by the courts for al-Megrahi to remain in prison while appealing his conviction.

al-Megrahi requests early release from prison on compassionate grounds.

al-Megrahi’s second appeal against his conviction is officially dropped following his request. Two days later, he is released from prison on compassionate grounds, and returns home to Libya on the plane of the country's leader, Colonel Muammar Gaddafi.

Scottish Parliament is recalled to discuss the release of al-Megrahi, with Justice Secretary Kenny MacAskill defending his decision.

al-Megrahi falls into a coma following his cancer diagnosis.

Colonel Gaddafi is killed by rebels during an uprising against him in Libya.

Abdelbaset al-Megrahi dies at his home in Tripoli at the age of 60.

Seven Libyans are named as suspected co-conspirators in the Lockerbie bombing.

To mark the anniversary of the bombing, Lord Advocate Frank Mulholland reaffirms they caught the right person in Abdelbaset al-Megrahi, and vows to find his accomplices.

The family of Lockerbie bombing victims are not allowed to pursue an appeal on al-Megrahi’s behalf, Scottish judges rule.

al-Megrahi’s family launch a new appeal in a bid to posthumously overturn his conviction for the bombing.

The Scottish Criminal Case Review Commission permits a fresh appeal of al-Megrahi’s conviction, on grounds of the potential of “an unreasonable verdict” and “non-disclosure” affecting the verdict. They turn the case over to the High Court of Justiciary.

The United States announce on the anniversary of the Lockerbie bombing that new charges have been filed against Abu Agila Mohammad Masud, who has been accused of making the bomb.

Scottish judges officially reject the appeal from al-Megrahi’s family, officially upholding the original verdict.

Abu Agila Mohammad Masud is taken into US custody. It’s reported that he confessed to setting the timer for the bomb 10 years prior, while in Libyan custody on unrelated charges.

Scheduled date for Abu Agila Mohammad Masud’s trial in Washington, US. He faces up to life in prison, or a $250,000 fine, for each charge he is convicted of. It has already been ruled he will not face the death penalty.

Lockerbie: A Search for Truth, which stars Colin Firth as Jim Swire, is available now on Sky Atlantic and NOW.

A four-part documentary on the tragedy is also available now on Sky Crime on demand via Sky Go or by streaming on NOW.

You can find out more about the documentary here.