“Those that were not killed instantly, screamed as they lay there wounded. Lieutenant Hardow gave orders to clear the trench to the left towards 3rd Company, but the tank was already on them too. Then the panic started, everyone from 1st and 3rd Companies jumped out of the trench and ran the fastest race of his life, pursued by the merciless tank machine-gun fire which cut down many men as if it were a rabbit-shoot. The troops that ran wildly from the enemy were experienced soldiers and they only stopped running when they reached the lane from Boiry to Guemappe about one kilometre away.”

- Feldwebel Wilhelm Speck, 84th Reserve Regiment on facing a German tank for the first time.

“The first machine-guns were soon in action and found easy targets. . . . The Germans spotted some of the gaps in the British wire and their machine-guns soon turned these narrow alleys into death-traps. . . . It was in these open spaces in the middle of No Man's Land that the German machine-gunners found their choicest targets. From their trenches came the 'tac-tac-tac' of the guns as they traversed to and fro along the endless lines of advancing men. Whole waves were swept over by the fire. Wave after wave of the Geordies were cut down but still they kept coming on. . . . Furiously the German machine-gunners fired belt after belt of bullets into this fantastic target.

By the end of the day 57,470 British soldiers were down, a casualty rate of 75 percent which was never equalled in a British battle. The Germans lost 8000 men, one for every seven they cut down.

Denis Winter, in one of the few good and detailed historical assessments of weapons performance in combat conditions, adds the following technical reasons for the effectiveness of the machine-gun:

This rather than speed of fire was the trump card of the machine-gun—accuracy. On its tripod the machine-gun became a nerveless weapon; the human factor of chattering teeth, dripping sweat and feces in man's pants was eliminated. A terror-stricken man could fire his machine-gun accurately even by night. Moreover the weapon, though with the fire power of fifty riflemen, occupied a front just two feet in length, and thus presented a minute target to enemy snipers or batteries. The end product was indisputable. Six machine-guns could hold up a brigade; one gun could halt two battalions before they had got 200 yards from their front line. In Liddell Hart's opinion it was the machine-gun above all other weapons which held the armies fast.”

“The days go by and the incredible hours follow one another as a matter of course. Attacks alternate with counter-attacks and slowly the dead pile up in front of us...

Haie Westhus drags off with a great wound in his back through which the lung pulses at every breath. I can only press his hand; “It’s all up, Paul,” he groans and he bites his arm because of the pain. We see men living with their skulls blown open; we see soldiers run with their two feet cut off, the stagger on their splintered stumps into the next shell-hole; a lance corporal crawls a mile and a half on his hands dragging his smashed knee after him; another goes into the dressing station and over his clasped hands bulge his intestines; we find one man who has held the artery of his arm in his teeth for two hours in order not to bleed to death. The sun goes down, night comes, the shells whine, life is at an end.

Still the little piece of convulsed earth in which we lie is held. We have yielded no more than a few hundred yards of it as a prize to the enemy. But on every yard there lies a dead man.”

“The 22nd April was a glorious spring day. Air reconnaissance in the morning had disclosed considerable liveliness behind the German lines and some activity in the Houthulst Forest (2 miles north of Langemarck), where a column was seen on the march, though it tried to evade observation; but there was nothing abnormal in this. In the forenoon there was considerable shelling of Ypres by 17-inch and 8-inch howitzers and lighter guns, and towards midday, of the roads leading into the town; but this gradually ceased and all was quiet again.

Suddenly, at 5 p.m., a new and furious bombardment of Ypres by heavy howitzers was recommenced. The villages in front of Ypres, almost untouched until then, were also heavily shelled, and simultaneously French field-guns to the north-east of Ypres began a somewhat rapid fire, although the German field artillery was silent. At first some officers who heard the firing surmised that the newly arrived Algerian Division was "shooting itself in"; but those who were on points of vantage saw two curious greenish-yellow clouds on the ground on either side of Langemarck in front of the German line. These clouds spread laterally, joined up, and, moving before a light wind, became a bluish-white mist, such as is seen over water meadows on a frosty night. Behind the mist the enemy, by the sound of his rifle fire, was advancing. Soon, even as far off as the V Corps report centre at "Goldfish Chateau" (2,000 yards west of Ypres railway station and five miles from Langemarck) a peculiar smell was noticed, accompanied by smarting of the eyes and tingling of the nose and the throat. It was some little time, however, before it was realized that the yellow clouds were due to the gas about which warnings had been received, and almost simultaneously French coloured troops, without officers, began drifting down the roads through the back areas of the V Corps. Soon afterwards French Territorial troops were seen hurriedly crossing the bridges over the canal north of Ypres. It was impossible to understand what the Africans said, but from the way they coughed and pointed to their throats, it was evident that, if not suffering from the effects of gas, they were thoroughly scared. Teams and wagons of the French field artillery next appeared retiring, and the throng of fugitives soon became thicker and more disordered, some individuals running and continuing to run until they reached Vlamertinghe and beyond. Although the "seventy-fives" were firing regularly, it was obvious that something very serious had happened, and this was emphasized when, about 7 p.m., the French guns suddenly ceased fire.”

On March 1, 1917, the American public learned about a German proposal to ally with Mexico if the United States entered the war. Months earlier, British intelligence had intercepted a secret message from German Foreign Minister Arthur Zimmermann to the Mexican government, inviting an alliance (along with Japan) that would recover the southwestern states Mexico lost to the U.S. during the Mexican War of 1846-47.

The secret to the British interception began years earlier. In 1914, with war imminent, the British had quickly dispatched a ship to cut Germany’s five trans-Atlantic cables and six underwater cables running between Britain and Germany. Soon after the war began, the British successfully tapped into overseas cable lines Germany borrowed from neutral countries to send communications. Britain began capturing large volumes of intelligence communications.

British code breakers worked to decrypt communication codes. In October of 1914, the Russian admiralty gave British Naval Intelligence (known as Room 40) a copy of the German naval codebook removed from a drowned German sailor’s body from the cruiser SMS Magdeburg. Room 40 also received a copy of the German diplomatic code, stolen from a German diplomat’s luggage in the Near East. By 1917, British Intelligence could decipher most German messages.

What led to the proposal of alliance to Mexico? Zimmermann sent the telegram in anticipation of resumption of unrestricted submarine warfare, an act the German government expected would likely lead to war with the U.S. Zimmermann hoped tensions with Mexico would slow shipments of supplies, munitions, and troops to the Allies if the U.S. was tied down on its southern border.

Some suspected the telegram might be a forgery to manipulate America into the war. However, on March 29, 1917, Zimmermann gave a speech in the Reichstag confirming the text of the telegram and so put an end to all speculation as to its authenticity.

The Zimmermann Telegram galvanized American public opinion against Germany once and for all. The telegram was considered perhaps Britain’s greatest intelligence coup of World War I and, coupled with American outrage over Germany’s resumption of unrestricted submarine warfare, was the tipping point persuading the U.S. to join the war.

At the beginning of World War I the belief that victory came from mass infantry charges dominated military thinking in spite of the introduction of rapid‐firing small arms and artillery. After the first Battle of the Marne thousands of miles of parallel trenches were dug along the Western Front, linked by intricate systems of communication trenches and protected by barbed wire. With such trenches stretching from the North Sea to Switzerland, a stalemate existed and to break it various new weapons were introduced, including hand‐grenades, poison gas, trench mortars, and artillery barrages. Consequently casualties hitherto undreamed of followed every mass infantry attack.

“We were one of the first brigades ever to see a tank, I think. We were ear-marked to do our third attack in the Somme towards the middle of September when the tanks were first to be used, and so we were allotted one of the first tanks to land in France to do some training with our brigade. Everybody was staggered to see this extraordinary monster crawling over the ground, and we did what training we could with this one tank. Learning to follow the tank at suitable intervals and that sort of thing. It was a very limited amount of training you could do with one tank…

And we saw these tanks coming over for the first time; they’d never been used before. It was a funny sensation to see a dozen tanks coming over shell holes, no stopping. Didn’t matter what they came over, they got over it alright, and it was horrifying. It gave you a funny sensation to think that all these were coming and they were on our side, they weren’t against us! But we realised that this was the very first time they’d ever been used. The 15th, I think it was the 15th of September, and you could see them coming and then when they got level with you and then they’d go over up to the front line. It was a wonderful sensation, really, to see them. But it was horrifying, you know…

It was a complete and utter surprise to the Germans that we ever had devised such a thing as a tank. They were so shattered when they first appeared on the Somme. The mistake we made then was as there was no opposition we were not prepared for that. Why didn’t we have our cavalry all ready to take over from the tanks and wipe the whole thing out? We could have turned the flank of the Germans in no time. But it took us by surprise, the success of the tanks, and we were so ill-prepared that nobody followed them up.”

-British soldiers at the Battle of Somme