"Two years in the making. Ten minutes in the destroying." The moving words attributed to a Pal, from one of the famous World War One battalions.
The idea was men from the same village, town and city would be keener to sign up if they would serve alongside friends and workmates. There were sporting and artists battalions, even one made up of stockbrokers.
The tragedy of the Pals was that huge swathes of young men from one place were wiped out.
Statistics from WWI are shockingly heartbreaking. One in seven of the adult male population of Britain died - twice as many as in the Second World War. Sixty per cent of all officers involved on the first day of the Somme were killed.
The Sheffield Pals was raised in autumn 1914 during a heady rush of patriotism which gripped the country.
And the gallant young men of our city were quick to sign up for the Sheffield Pals - the 12th Yorks and Lancaster Regiment (Sheffield City Battalion). In total, 52,000 heroic men from Sheffield served in the Armed Forces in WWI.
The Pals started their training at Bramall Lane before moving to Redmires Cam on the outskirts of the city. The remains of the trenches they dug to replicate as best they could conditions on the Western Front can still be found.
Training moved to Staffordshire, then they were sent to Egypt before being shipped to France in 1916 to prepare for the great push at the Somme.
The Sheffield Pals fought alongside the Accrington Pals on that fateful first day.
Saturday, July 1, the first wave went over the top and into No Man's Land.
That day, 513 officers and men were killed, wounded or missing, with 75 slightly injured.
Richard Sparling, a sports journalist with the Sheffield Daily Telegraph, described the carnage as the Sheffielders moved to the front line.
"The 1st of July, 1916, will be remembered as one of the saddest and most tragic, yet withal one of the most glorious pages of Sheffield history, for on that day there fell in battle the largest number of Sheffield men ever known. Around it sacred memories will ever cling as citizens recall the gallant men who in a few minutes put to the test their long months of training."
He recalled No Man's Land with those 'glittering triangle, every triangle a symbol of dead, dying and wounded.
Among those were Arthur Greensmith, of Sharrow, an engineering student. His body was never found.
On July 18 after hearing nothing from her beloved brother for weeks, his sister Cecilia wrote him a heartbreaking letter in which she said: "I hardly know how to begin to write to you, my heart is nigh bursting first with hope and then despair."
In September 1916 his death was confirmed , but not before his family made desperate efforts to try to find out if he had been injured and was unable to write or had been taken prisoner by the Germans.
Reg Glenn, of Sheffield, was one of those to survive the conflict but never forgot the hoor of seeing the bodies of fallen comrades killed on the disastrous first day of the battle still lying in No Man's Land eight months later.
He once described that first day as having a 'perfectly blue Mediterranean sky with skylarks singing'.
Reg lived till he was 101, dying in 1994, one of the final survivors of WWI, regularly speaking regularly about his experiences.
Richard, Arthur and Glenn are just three of the millions of reasons why we must never forget.