Robert Black was one of the UK's most notorious serial killers.

Convicted of four child murders and a range of other sex crimes, the delivery driver who stalked the roads of Britain and Ireland for his young victims has long been suspected of involvement in other unsolved disappearances.

He was born in 1947 near Falkirk in Scotland to single mother Jesse Hunter Black.

The factory worker put her son up to be fostered within weeks. The couple that took him in were in their 50s and lived in Kinlochleven in the West Highlands.

Within 11 years both had died, and Black was placed in a children's home back in Falkirk. There his proclivity for sexual violence emerged when, as a 12-year-old, he was accused of trying to rape a young girl.

He was moved to a Musselburgh all-boys home, where he claimed to be the victim of sexual abuse at the hands of a male staff member.

When there he would walk the short distance to Portobello to swim and work as a lifeguard at the coastal resort's swimming pools.

Twenty years later one of his victims, Caroline Hogg, would disappear close to those same pools.

When he turned 15, Black left the home in Musselburgh and moved west again, to Greenock.

A year later, in 1963, he faced the courts for the first time after molesting a seven-year-old girl in an abandoned air raid shelter.

He lured her from a swing park with the promise of showing her a box of kittens, then attacked.

Yet he was not incarcerated for the crime, receiving only a caution for lewd and libidinous behaviour.

Black relocated back to Falkirk where he started dating his one and only girlfriend. Black even asked her to marry him, but was rebuffed and the relationship ended acrimoniously.

Three years after attacking the girl in Greenock, he was reported for abusing the daughter of a couple he was lodging with.

In 1967 he was found guilty of three counts of indecent assault and sent to borstal in Polmont, outside Falkirk, for a year.

Black moved to London and again found work as a swimming pool attendant, where he could indulge his fetish for young girls in swimsuits.

In 1976 he secured a job with a London-based delivery firm. Delivering posters throughout the UK for more than a decade, he was able to roam the country as an anonymous van driver.

Much of his abuse took place in the back of this van.

A delivery run took him past Coldstream in 1982 when he snatched Susan Maxwell, then back to Portobello a year later when he kidnapped Caroline Hogg from the promenade, and through Leeds in 1986 when he abducted Sarah Harper.

In Northern Ireland in 1981, on a rural road in Co Antrim, he snatched nine-year-old Jennifer Cardy as she cycled to a friend's house.

After being caught red-handed in Stow, with a barely conscious victim in the back of his Ford Transit, he claimed that was his only "slip" - the only time he ever kidnapped a young girl in his van.

Four murder convictions followed, and Black spent the rest of his life in jail.

He died in Maghaberry Prison near Lisburn aged 68.