New £5 coin commemorates the courage of Portsmouth '˜Boy Hero' Jack Cornwell

And now, a century after Portsmouth sailor Jack Cornwell died, the 16-year-old’s heroism has been immortalised in a new £5 coin.

The coin depicts the young sailor at his post as the last surviving gunner aboard the stricken HMS Chester.

The lettering around the edge reads ‘Mother, don’t watch for postie’ – a quotation from The Ballad of Jack Cornwell, by Charles Causley.

The commemorative item was unveiled this month at the Imperial War Museum by Jack’s great-great nephew, Alex Saridis.

Alex followed in his heroic ancestor’s footsteps and recently completed his training course with the Royal Navy at HMS Raleigh.

The 23-year-old Able Seaman now serves aboard Portsmouth-based frigate HMS Iron Duke.

Alex said: ‘It’s a great honour that Uncle Jack has been recognised in this way. I am glad to see his sacrifice and courage is remembered all these years on.’

The young sailor said that during his time at Raleigh, he and all his fellow cadets were told stories of Jack’s courage under fire.

The teen joined HMS Chester as a gunner sight setter.

Within the month, he would be killed – cut down by mortar debris in the Battle of Jutland, in the icy North Sea.

His ship had taken 17 direct hits from German artillery fire, wiping out much of the crew.

But, even with the bodies of his shipmates strewn around him, Jack clung on at his post in ‘dutiful silence’ by his gun.

Miraculously, his ship escaped the bombardment and Jack was transported to hospital in Grimsby. He died three days later.

His heroics earned him a posthumous Victoria Cross, which sits in the Imperial War Museum alongside one of Chester’s guns.

The Royal Mint has been making official military campaign medals since it was commissioned to make awards for soldiers who fought in the battle of Waterloo in 1815.

Jack’s coin is one of a series of six being issued by the Royal Mint to mark the centenary of the First World War.