The Disappeared are those who were abducted, murdered and secretly buried by republicans during Northern Ireland's Troubles.
Despite extensive and painstaking searches, the bodies have never been found of seven out of 16 people listed by the commission set up to locate victims' remains.
Here is a timeline charting more than 40 years of developments in one of the darkest episodes of Northern Ireland's Troubles.
Joe Lynskey was a former Cistercian monk from the Beechmount area of west Belfast, who later joined the IRA. Mr Lynskey's name was added to the list of the Disappeared in 2010 when republicans claimed he was "executed and buried" by the IRA. His body has not been found.
Kevin McKee, 17, was the youngest member of the Disappeared. He was abducted alongside fellow IRA member Seamus Wright, 25. The pair are interrogated and murdered by his former colleagues who accuse them of being British army agents and members of its undercover Military Reaction Force. Despite extensive searches in Coghalstown, near Navan in County Meath, their bodies have never been found.
Jean McConville, a widow and mother-of-10, is taken by the IRA from her home in the Divis Flats in west Belfast. The case initially gains extensive media attention in the run-up to Christmas as her children plead for information about their mother. However, republicans put out the message that she is merely lying low, and the story gradually fades. Her body was found at a beach in County Louth in 2003.
Peter Wilson, 21, vanishes from his Falls Road home in west Belfast. Described as a vulnerable person with learning difficulties, for four days before he disappeared he lived with an Army unit at their headquarters near his home. At the time the Army was accused of using a vulnerable person to gather information on the IRA, but the Army said they wanted him to experience military life. Reports suggest he may have been abducted and murdered by the IRA. His name was added to the list of the Disappeared in 2009 after new information became available. His remains were found in November 2010.
Eamon Molloy, 22, is kidnapped and shot dead by the IRA over claims he is a police informer. His body was discovered in a cemetery near Dundalk, County Louth, in 1999.
The IRA abducts and murders Columba McVeigh, a 17-year-old from Donaghmore, County Tyrone. He had allegedly confessed to being a British army agent with instructions to infiltrate the IRA. Despite a number of extensive searches at Bragan Bog near Emyvale, County Monaghan, his body has never been found.
Captain Robert Nairac, 29, is abducted by the IRA in south Armagh. The SAS-trained officer is taken from outside a pub where he had been singing Irish rebel songs and brought across the border to a field at Ravensdale, County Louth. His body has never been found.
Brendan Megraw, 23, is abducted and murdered by the IRA, who claimed the Belfast man had confessed to being an undercover British agent. His wife was expecting their first baby at the time. Despite extensive searches, his body has never been found.
Friends Brian McKinney, 22, and John McClory, 18, are abducted and murdered after being accused of stealing IRA weapons for use in robberies.
Their bodies were uncovered near a bog in County Monaghan in 1999.
Gerard Evans, 24, goes missing in County Monaghan while hitchhiking home to Crossmaglen in south Armagh. No group has ever admitted his murder. His remains were recovered in County Louth in 2010.
Eugene Simons, 26, goes missing from his home near Castlewellan, County Down, on New Year's Day. His body was discovered by chance in May 1984 in a bog near Dundalk, County Louth.
Danny McIlhone goes missing from his west Belfast home. The IRA said Mr McIlhone was not suspected of being an informer but was being questioned about stealing weapons - it was claimed he was killed in a struggle with the person who was guarding him. His remains were found in 2008.
Charlie Armstrong, 57, goes missing on his way to Mass in Crossmaglen. His remains were found in 2010.
Body of Eugene Simons is discovered.
Seamus Ruddy, 32, originally from Newry, County Down, goes missing. He had been working as a teacher in Paris. It is believed he was killed by members of the INLA. Fresh searches were carried out in 2008 after his family were told his remains were in a forest in Normandy, but they found nothing.
The IRA announces a "complete cessation of military operations". This ceasefire holds until the bomb in London's Docklands in February 1996.
The INLA admits it killed Newry man Seamus Ruddy.
The IRA announces its second ceasefire.
The Good Friday Agreement is signed, following years of intensive peace talks between political parties in Northern Ireland and the British and Irish governments.
Bereavement counselling group WAVE sets up a confidential freephone number for anonymous callers to provide information on the Disappeared. In the same month, an IRA spokesperson acknowledges to the newspaper An Phoblacht/ Republican News that the IRA secretly killed and buried "a small number of people" in the 1970s. The interview said the IRA had set up a special unit to trace the bodies.
Information emerges to suggest Newry man Seamus Ruddy is buried in Rouen, France, but nothing is found in subsequent searches.
The IRA admits it has located the graves of nine people it abducted and killed in the 1970s and 1980s. It claims most of those they had murdered had been giving information to the British security forces, an allegation denied by the victims' families.
The Independent Commission for the Location of Victims' Remains (ICLVR) is established by a treaty between the British and Irish governments. The commission's purpose is to obtain information that may lead to where the remains of the Disappeared are buried. Information given to the commission is strictly confidential and is not passed to other agencies or used in prosecutions.
The remains of the first of the Disappeared - Eamon Molloy - are recovered near Dundalk, County Louth, and returned to his family for burial. His remains had been placed in a coffin and left above ground at Faughart cemetery.
In a separate development, the IRA provides information about the location of the Disappeared to the ICLVR through intermediaries. As a result of this, digging begins at six sites in the Republic of Ireland.
The remains of Brian McKinney and John McClory are discovered in a double grave after 30 days of searches at a bog in Colagh, County Monaghan.
The remains of Brian McKinney and John McClory are returned to their families, 21 years after their disappearance. Both men are laid to rest in Milltown Cemetery in west Belfast. Brian McKinney's mother Margaret tells the Irish News: "I wouldn't have wanted to go to my grave without Brian being properly buried. For years I've had nowhere to mourn him. Now I'll be able to go to his grave and talk to him. I'll have somewhere to bring flowers and to cry."
Remains unearthed by a dog walker at a beach at Shelling Hill, County Louth, are thought to be those of Jean McConville.
A third search for the remains of Columba McVeigh at a bog at Bragan, County Monaghan, ends without success. The latest dig concentrated on an area about the size of a football field, adjacent to where previous searches took place in 1999 and 2000.
DNA tests confirm that remains found buried on a County Louth beach are those of Jean McConville. Irish police confirmed that she had died from a bullet wound to the head. Her remains are returned to her family, and her funeral takes place in Belfast.
The IRA issues a statement apologising for the grief caused to the families of the Disappeared, saying it was sorry their suffering had continued for so long. The apology is dismissed by the families of Jean McConville and Columba McVeigh.
The mother of Columba McVeigh dies at the age of 82. A tireless campaigner for the return of her son's body, she had been ill for some time.
The remains of Danny McIlhone are discovered at bogland near the Blessington Lakes in County Wicklow, following information given to the ICLVR. In a statement, his family said: "We as a family are now at peace and now have the opportunity to given our brother Danny a Christian burial and to lay him to rest with our beloved mother and father." The discovery followed two unsuccessful searches in 1999 and 2000.
The Independent Commission for the Location of Victims' Remains begins investigating the disappearance of Peter Wilson.
Legislation comes into force to allow families of the Disappeared whose bodies have not been found to settle their affairs. Under the Presumption of Death Act, the families of missing persons will, for the first time, be able to have the presumed death of their family member confirmed by the High Court, and a certificate of presumed death made available to them by the General Register Office.
The name of west Belfast man Joe Lynskey is added to the list of the Disappeared. A spokesman for the Independent Commission for the Location of Victims' Remains says he is satisfied the case "falls within its remit". It follows a number of newspaper reports based on briefings from "senior republican sources" that the IRA had murdered Mr Lynskey.
The remains of Charlie Armstrong are discovered in a bog in County Monaghan. The discovery is made less than 300 metres away from where the bodies of Belfast friends John McClory and Brian McKinney were found more than 11 years previously.
Charlie Armstrong's funeral takes place in Crossmaglen, almost 30 years after he went missing.
The remains of Gerry Evans are found at a site in Carrickrobin, County Louth, following searches based on information given to the ICLVR. His remains were discovered shortly after it announced its search at the site was winding down. They had unearthed an area the size of four football fields during 16 months of painstaking excavation but had found nothing. Mr Evans was laid to rest in the grounds of St Patrick's Church in Crossmaglen, not far from the grave of Charlie Armstrong.
The remains of Peter Wilson are discovered at Waterfoot beach in County Antrim. Archaeologists and other experts were sent to the beach in the Glens of Antrim after a tip-off to the ICLVR. His sister, Anne Connolly, said it had been a shock to learn he might be buried in Waterfoot as her mother, Lily, who died three years previously, had often visited the beach.
DNA tests confirm that a body exhumed from a graveyard in Scotstown, County Monaghan, are not those of Columba McVeigh.
Another search for the remains of Columba McVeigh begins in Bragan, County Monaghan, but it is abandoned a few weeks later because of bad weather. It resumes in the spring but again nothing is found.
A sixth search for the body of Columba McVeigh ends in failure. Trees are cleared at Bragan Bog, County Monaghan. However, nothing is found.
The ICLVR issues a fresh appeal for information about the location of the remains of the Disappeared. It follows the broadcast of a BBC/RTÉ documentary highlighting the plight of families with missing relatives.
A former IRA leader is charged in connection with the 1972 abduction and murder of Jean McConville. Ivor Bell, 77, who was a senior leader in the Provisional IRA in the 1970s, is arrested at his home in Andersonstown. The case against him is based on an interview he allegedly gave to researchers at Boston College in the US. He is released on bail.
Sinn Féin President Gerry Adams is arrested in connection with the 1972 murder of Jean McConville. He presents himself at Antrim police station for questioning. In a statement he says: "While I have never disassociated myself from the IRA and I never will, I am innocent of any part in the abduction, killing or burial of Mrs McConville." After four days of questioning, he is released. Police said a file would be sent to the Public Prosecution Service.
The sister of Seamus Ruddy says she knows the names of his killers. Anne Morgan, who was the last family member to see Mr Ruddy alive, says: "We want them to come forward and to show the right place where our Seamus is buried."
Relatives of Columba McVeigh and Brendan Megraw say finding their loved ones' remains is more important than justice.
Forensic work begins in the search for Brendan Megraw, who was abducted and murdered in 1978. The Independent Commission for the Location of Victims' Remains carries out a 'geophysical survey' on land not previously searched at a bog in Oristown, County Meath. There have been three unsuccessful searches for him, the most recent in 2010.
Human remains found on 1 October in a search of bogland in County Meath are confirmed as being those of Brendan Megraw, following DNA tests. His brother Kieran spoke of his family's relief. "He has been alone for nearly 40 years and now we can bring him home and lay him to rest with our mum and dad. We want to thank all those who have supported us over the years."
A fresh search begins at at bog in Coghalstown, County Meath for the remains of Joe Lynskey. The search is taking place close to where Brendan Megraw was found in October 2014.
Investigators searching for Joe Lynskey in Coghalstown find two bodies in a single grave. Investigators believe that the remains may be those of Seamus Wright and Kevin McKee, who were thought to have been buried close to the site.
DNA samples confirm that the remains found in County Meath in June 2015 are those of Seamus Wright and Kevin McKee. Mr McKee's sisters, Maria and Philomena, describe the news as "bittersweet".
"We are so, so glad that, after 43 years, he will now be buried with our mother who never recovered from his disappearance."
The search for Joe Lynskey ends without his remains being found. Mr Lynskey's niece, Maria, said she was "bitterly disappointed" that his remains were not discovered, but adds: "This year I had hope when before there was nothing and I'm grateful for that."
Human remains are found at a site in northern France where investigators are searching for Seamus Ruddy from Newry. The search was launched after new information on the whereabouts of Mr Ruddy was submitted by the Irish Republican Socialist Party (IRSP) and former INLA members.
Sources in the IRSP claimed that Mr Ruddy went willingly with INLA members from Paris to the wooded area, where there was an arms dump. It is not clear what happened, but Mr Ruddy was shot dead and buried in a shallow grave. Sources claimed that INLA members returned to the spot the following day, removed the arms cache and buried Mr Ruddy where it had been.
While formal identification has not yet taken place, Mr Ruddy's sister, Anne Morgan, said the discovery had "completely changed" her life.
A fresh search for Columba McVeigh's remains begins in County Monaghan. It winds down in November 2018 after nothing is found.
A reward of almost £50,000 is offered for new information that results in the bodies of the Disappeared being found.
Another search for Columba McVeigh begins at Bragan Bog in County Monaghan.