Legend has it that an angel protected British soldiers at a battle in the First World War. Steven Russell hears from a man whose granddad swore it was true

'It was Christmas-time when I was talking to him about it. When I was asking what the angels had been like, he pointed to a card on the mantelpiece with a picture of an angel with wings outspread and said 'It was just like that.' It's quite emotional talking about it, really, because I can remember it as if it was yesterday.'

But it was decades ago that David Ludlow spoke to his granddad William George Ludlow. Bill, as he was known, had slipped up to London in 1914 to join up – underage, at 17 – and fight a German nation on the march.

Only three weeks or so after Britain went to war, the private in the Royal Fusiliers (City of London Regiment) found himself embroiled in the Battle of Mons in Belgium.

According to The Western Front Association (folk interested in First World War history) the first action for the men of the British Expeditionary Force came on August 23, 1914, when the German army attacked. 'They' – the Germans – 'suffered what was for the time enormous infantry casualties from the terrific rate of the rapid rifle fire of the British professional troops. The British volleys brought the Germans to a stall,' says the WFA website.

Trouble was, the enemy ranks were being swelled. The BEF commander decided to withdraw his outnumbered men. 'The ferocity of the battle on the 23rd… and the apparent stunning British victory over a superior force… immediately engendered a rumour that swept the British homeland: some form of divine intervention must have occurred.

'The rumour typically claimed that an avenging angel, clothed all in white, mounted on the classical white horse and brandishing a flaming sword, had appeared in a parting of the clouds at the worst moments of the night battle. The angel had rallied the troops and enabled them to crush the enemy and halt their advance. This apparition was soon called 'The Angel of Mons', though by whom remains obscure. It was also seen as a divine indication that God was on the side of the allies and, in the end, they would prevail over the central powers.'

The WFA account is clearly sceptical, calling it a mass illusion and pointing out many British troops were 'old soldiers' well versed in 'legends such as the 'shower of arrows' that saved the grossly outnumbered British at Agincourt. And indeed, in some accounts the soldiers claimed that there was a protective shield of bowmen around the BEF at Mons'.

Whatever the truth, the Angel of Mons story reached worried families in Britain, 'where any hope for a fortuitous and propitious course of events was a relief from the ceaseless and catastrophic casualty lists… eyewitness accounts of angel-like figures with outspread wings appeared in the media'. A legend was created.

But Bill Ludlow wasn't an old soldier with rheumy eyes. He was a young man. And he knew he'd seen the sky full of angels.

Bill saw some bad things as the war continued. It seems he fought at Ypres and on the Somme. By good fortune he survived, returned to his native Kent and became a labourer in the cement industry. But life didn't treat him that kindly. He was widowed when tuberculosis claimed his wife after their son, William George junior, was born. Bill raised the lad and then, once the boy had grown and married, lived with the couple.

David, the next generation, thus grew up with Bill an integral part of the family, 'and because of that I was very close to him. He had his own room in our house. I used to go up and see him every night; sit with him.' Grandfather didn't talk about his time as a soldier unless he was asked, though. 'He told me he had seen terrible things that no-one should see again.

'One day, when I was about 11 or 12, I was doing a project at school about the Battle of Mons and I asked him about it. 'You were there, weren't you?' He was answering in sort of 'yes' and 'no' terms. Then, when I said about the angels, he went into quite a bit of detail.

'My grandfather said he saw this angel: 20ft tall, outspread wings, hands behind her, holding back the lines. He could see her face plainly – beautiful, he said.'

So what does David think now?

'I've researched this and there's an awful lot of scepticism about it. People say it could be the men hallucinating. It could be cloud formation, or a phenomenon of the weather. It could be this; it could be that. At the end of the day, my grandfather wasn't a religious man in any shape or form. He had no reason to lie to me. He only told me what he saw. I won't say 'what he thought he saw', because he was 100% convinced what he saw was there. He told me with great conviction that he had seen the sky full of angels at Mons. They had their wings stretched up above them.

'He had no reason to make this up and he remained certain of this right up to his death from silicosis' – a lung condition almost certainly caused by his work in the cement plant grinding mill – 'in 1966.'

So you're convinced?

'Yes. Because of knowing the man. Knowing he was a very honest man. A simple man. Not simple as in doolally, but he was a simple, straightforward man.

'There's never smoke without fire, really, is there? It's all very well for people to say it could have been men hallucinating, but they couldn't all have been hallucinating at the same time.'

David forgot all about this until fairly recently. Wife Maggie is a member of Seraphim, the all-female vocal ensemble. David's on its management team. And he learned a Seraphim/Norwich Baroque concert on July 1 would give the first performance of a piece by composer Patrick Hawes… a composition called The Angel of Mons. 'I thought 'Oh, my granddad was at the Battle of Mons and he said he saw the angels.''

David's arranged to have it dedicated to Bill: presented in memory of William George Ludlow, 1897 to 1966. Veteran of the Battle of Mons. 'And it means that anyone else who performs it, it is there on the heading of the music.' It's something that makes David proud. 'When I go and see it, it's going to quite emotional, I should think.'

David and Maggie are both singers. They met 21 years ago during a Waveney Light Opera Group production of Iolanthe – Maggie, a flautist, playing in the pit and David on stage.

Does he expect to well up on the night?

'Well, being a performer most of my life, you tend to have a way of overcoming that. Whether I will or not, I don't know. I shan't be ashamed if I do,' he laughs.

On Saturday, July 1, Seraphim and Norwich Baroque present concert Love and Sacrifice at St Stephen's Church, Norwich.

It includes two works by East Anglian composer Patrick Hawes: The Angel of Mons and Song of Songs. There's also Baroque music, works by Purcell, Bach and Marcello.

Time: 7.30pm. Tickets: £16, £14, £5. From Norwich Theatre Royal box office (01603 630000), www.norwichbaroque.co.uk or on door.