Animals died in their thousands in the Great War, but they also served as morale-boosters to weary and half-broken men: not just the faithful dogs and horses, but goats, pigs and even a baboon. Corporal Jackie, who served with the 3rd South African Infantry, excelled at sentry duty.

In Nicholas Milton’s excellent new history, he recalls his own grandfather’s admiration for the ‘dogs with medical packs and red crosses on their backs’, bringing aid to soldiers wounded at Gallipoli. Often the dogs were targeted by snipers.

Yet one small, overlooked creature arguably had a greater impact than any other. The mosquito was murderous on the Balkan Front. ‘A significant proportion of those killed at Salonika died of malaria,’ says Milton. The sick were brought back to England, where one treatment camp was located on the Isle of Sheppey. Locals soon got malaria too, the Ministry of Health denying all responsibility.

Then there were the rats. ‘Every time you wake [they] are fighting and squeaking all over you,’ recalled Lieutenant Alfred Johnson. ‘The other night one took a flying jump at my face...’ For those already exhausted and suffering from shell-shock, the rats could tip them over the edge.

But it’s the dogs who give us the best stories. My favourite here is Fritz, who survived when a German trawler sunk by HMS Falmouth in 1914, floating on a plank of wood. The sailors renamed him Old Bill and he went on to survive the Battle of Jutland in 1916, though suffering three shrapnel wounds. He was rescued again when the Falmouth finally sank off Flamborough Head, and spent a happy retirement at Plymouth Barracks, being honoured on his death with a full naval funeral.

Dogs’ acute sense of hearing made them invaluable early warning systems, as they would run for cover when they heard shells incoming. One dog would even scrape himself a quick trench and lie as flat as possible, in wise imitation of his human comrades.

And then there were the noble, all-enduring horses. Of some one million horses who went to war for Britain, nearly half died. 

A great survivor was Warrior, belonging to Major General John Seely. He learned to gallop in a ‘swerve or zig-zag when he heard the pinging sound of bullets’, and took Seely safely through the last great cavalry charge of Moreuil Wood in 1918. 

They returned home to the Isle of Wight on Christmas Day, and afterwards spent many happy days riding out over Mottistone Down. In 1938, they took a centenary ride there, having reached a combined age of 100. It must have felt a long way from Ypres. 

Warrior died in 1941, aged 32.