Every day, Philomena Lynott goes the few yards from her home to the cemetery overlooking the sea where her rock star son Phil lies.

She goes to ‘wash his face’ – taking two jugs of water to clean the gravestone which attracts a stream of fans from all over the world, leaving flags, letters, plectrums and floral tributes.

And she goes to ‘kick’ that gravestone in St Fintan’s cemetery, Sutton – a seaside suburb of Dublin.

“I shout and I bawl at him, I tell him all my news and that’s the way it is,” she says. “And I do kick him, you’re quite right. I spent the first ten years crying my eyes out. I don’t know where the tears came from.”

Phil Lynott died on January 4 1986 of heart failure and pneumonia, aged 36, his final years dogged by drug and alcohol abuse. But his music and his reputation as the first black Irishman of legend live on.

A statue of him was erected off Grafton Street in Dublin, in 2005. An annual Vibe For Philo in Dublin, celebrating his life, now attracts thousands from all over the world.

On Friday, a major exhibition, mounted by Ireland’s Hot Press magazine, opens in Dublin’s Stephen’s Green shopping centre, featuring Phil’s guitars, notebooks and Thin Lizzy memorabilia. It comes just a month after the death of another Thin Lizzy member, guitarist Gary Moore.

Among the exhibits will be Phil’s framed Manchester United share certificate and photos of him with United stars George Best and Steve Coppell. Phil loved United and loved Manchester, but his mother’s passion for the city runs even deeper.

“Manchester is the warmest and loveliest city,” she says from her home in Dublin. “I was down and out when I’d had my little black baby. In those days to have a child out of wedlock, you were spat on, battered, beaten. I’d been thrown into a home for unmarried mothers.

“But when I settled in Manchester I found it the warmest city. I met wonderful people there.”

Philomena, now 80, had come to England to find work, and met Phil’s father, an immigrant from British Guiana, in a dancehall attached to a displaced persons hostel in Birmingham. Phil was born in 1949, and seeking a place where the single mother of a mixed-race baby would be accepted, Philomena ended up in Moss Side.

“Moss Side then, 50 years ago, was beautiful – leafy avenues, Alexandra Road, the park, everything,” she says.

When Phil was four, Philomena’s mother took him back to Dublin.

“And I ended up taking three jobs so I could send my mother money for keeping him,” says Philomena. “I worked in a dress shop near Lewis’s on Market Street, and all the clothes had film star names in them, like Rita Hayworth.

“Then I took a job as a barmaid, and on Saturdays I helped on a market selling beautiful Dannimac coats that were seconds.”

But in 1966, she took charge of the Clifton Grange Hotel in Whalley Range. “It had a nickname, the Showbiz Hotel because around that time all I took was showbiz people,” she says.

The guests – singers, dancers, comedians, contortionists – played the cabaret clubs of Manchester. Because of their working hours, the Showbiz’s bar did not usually open until 2am, bedtime was 6am and breakfast midday.

“I was only supposed to serve to my residents, but I was very naughty,” Philomena confesses.

So the night-time drinking sessions began to attract footballers – it was a home from home for George Best – and the group of criminals dubbed the Quality Street Gang. One such was Jimmy ‘The Weed’ Donnelly.

On his visits to Manchester, Phil Lynott met and befriended these characters.

He even wrote songs about this colourful fraternity – one song called Clifton Grange Hotel, another Johnny The Fox Meets Jimmy The Weed.

Thin Lizzy’s enduring song The Boys Are Back In Town is also believed to be a reference to the Quality Street Gang

“All of those people came in my bar and Philip liked them. They were characters,” says Philomena “He loved the nickname Jimmy The Weed. When the song became a hit, he gave Jimmy his own gold album. And Jimmy came over for his funeral.

“Years later we read that Jimmy was a member of the Quality Street Gang. If there ever was such a gang – and I did meet most of them that got named – they were lovely people. Gangsters today are going round shooting people. I never heard of those boys shooting anybody.”

Philomena has a rather different view of another public enemy of that era – the Sex Pistols. After one of TV’s most infamous moments, in 1976, when the Pistols swore repeatedly during a live interview with Bill Grundy, Johnny Rotten and co found it difficult to get a hotel room in Manchester. They pitched up at Philomena’s door, soaking wet, and were given a five-bed room nicknamed the Barracks.

“They came down to the bar and we had a great night,” she says. “They were the nicest-mannered... I’ve never forgotten them.”

In 1980, Philomena moved back to Dublin. But after Phil’s death, every Christmas for 20 years, she escaped the sadness of being in her home city and returned to Manchester to stay with friends.

“He didn’t learn how to say no. People would demand things of him and I suppose, like dear old Georgie Best, he started attracting the wrong crowd,” says Stuart Clark, deputy editor of Hot Press, of Phil Lynott. “He felt he had to keep proving himself. Maybe if he’d taken a break at that time, he’d still be here.”