The NZ and A Division sailed to the Aegean in April, leaving behind (to their dismay) the Mounted Rifles Brigade, the Otago Mounted Rifles, and the 1st Australian Light Horse. It was part (with the 1st Australian Division) of the Australian and New Zealand Army Corps (abbreviated ANZAC), itself part of the Mediterranean Expeditionary Force under General Sir Ian Hamilton. The MEF was to seize key points on the Gallipoli Peninsula and help the Navy through the Dardanelles – a huge amphibious operation mounted with extreme haste against the forewarned Turks.

The Australian division began landing at first light on Sunday, 25 April, 13 miles north of Cape Helles, on a rocky shore fit for mountain goats rather than laden soldiers clambering upwards under fire. Companies and battalions soon became hopelessly intermingled and, when the New Zealand Infantry Brigade began to reinforce the left at noon the situation was highly confused. The Auckland Battalion came in first, through a curtain of Turkish shrapnel, then two companies of the Canterbury Battalion, and then the Otago Battalion. All were at once dispatched to the front where they were hotly engaged. Withering shrapnel sprayed the foremost troops, the Turks counter-attacked strongly, and much valuable ground gained in the first advance had to be given up. Not until next day did the New Zealanders hear the comforting sound of their own guns, and the naval guns could do little to help. A toehold on Gallipoli 2,500 yards long by about 1,000 wide had nevertheless been won, and reinforcements – the Wellington Battalion among them – and supplies were arriving and wounded departing over two makeshift piers in what was to become known as Anzac Cove.

The British 29th Division had similarly failed to win its objectives on Cape Helles, but its small gains there seemed for the moment secure. At Anzac there was high-level talk of immediate evacuation, but Sir Ian Hamilton (like the men at the front) would not hear of it, though he continued to regard the Anzac affair as subsidiary and decided to reinforce the Helles landings with the Royal Naval Division and a French division. Off the narrow waist of the peninsula at Bulair the Royal Naval Division staged a demonstration to pin Turkish forces there. As part of this a young officer, B. C. Freyberg, swam ashore at night and lit flares, winning for himself a D.S.O. New Zealand was to hear more of him.

Sixteen Turkish battalions under Mustapha Kemal attacked Anzac on 27 April to drive the invaders into the sea; but their combination broke down, the local thrusts were all beaten back with heavy loss, and the Anzac front, a staff officer's nightmare, held firmly. Four naval battalions then landed and the units in the line were by degrees relieved and sorted out. Strenuous efforts were made to straighten the line, particularly by Canterbury and Otago, in the night 2–3 May, but they failed and the tired troops had to make do with existing positions, strengthening them by digging, mining, wiring, and roadmaking. Bit by bit all positions acquired names which became symbolic of Anzac daring, skill, and hard work. In front of Quinn's Post, scene of continual bombing, the Turkish lines were barely 30 yards off; behind it the ground fell away to form a cliff. A more vulnerable position would be hard to imagine, yet the troops hanging on there by their eyebrows knew that it must be held; for behind it was Monash Gully leading down to Shrapnel Valley, the main supply route. Tiny Plugge's Plateau (pronounced “Pluggie's”), overlooking the latter, was crowded with guns and howitzers, and below it was the beach. All saw their daily scenes of gallantry and defiance; for nowhere on Anzac was safe.

For lack of room at Anzac, one New Zealand battery went to Helles on 4 May and next day the infantry brigade followed. On the eighth the New Zealand infantry made two thrilling charges across the “Daisy Patch” towards Krithia, gaining 500 yards but losing 800 men (compared with 931 in the first three days at Anzac). An Australian brigade, charging in similar heroic fashion across the flat against countless machine guns, lost 1,000 men.

The mounted rifles and 1st Australian Light Horse (minus horses) reinforced the Anzac landing soon afterwards and on the nineteenth were severely tested. The Turks attacked repeatedly all along the line and were everywhere repulsed in a grim slaughter, more than balancing the Helles account. Next day the infantry brigade returned and found the Anzac front quiet, though gruesomely strewn with Turkish corpses. On the twenty-fourth there was an armistice to bury the dead. June started with a raid from Quinn's as part of a scheme to distract attention from a big Helles attack; both the Anzac and Helles thrusts were strongly opposed. At the end of the month the Turks made their last attempt to push the invaders off their soil, first at Helles and then before dawn on the thirtieth at Pope's and Russell's Top, where three battalions swarmed bravely across no-man's land and were cut down almost to a man.

From then onwards, apart from the daily shelling to which the Anzac guns, starved of ammunition, could seldom reply, and the ceaseless bombing at Quinn's, the front was quiet. Thirst, vermin, and flies in the fierce summer heat were enemies as relentless as the Turks. In August the MEF, strongly reinforced, staged a great offensive: heavy attacks at Helles and Anzac to pin down Turkish reserves, a tremendous and complicated assault on the commanding feature, Sari Bair, by a mixed force under Godley including the NZ and A Division (less the 1st Light Horse), and the landing of a fresh corps at Suvla Bay to extend the Anzac front northwards. All demanded immense and difficult preparation. All four mounted rifles regiments and the Maori Contingent (fresh from Malta) climbed tortuous slopes and scaled cliffs silently and irresistibly to gain the western foothills of the Sari Bair massif by 1 a.m. on the seventh. Then the New Zealand infantry passed through but failed to gain the crest at Chunuk Bair. The Wellington Battalion and the Gloucesters tried again at dawn on the eighth, reached the crest, and won a breathtaking view of the Dardanelles. All day the Turks showered them with grenades, enfiladed them with machine guns, and sprayed them with shrapnel; but they held on just below the crest, joined in the late afternoon by a gallant party of the Auckland Mounted Rifles. Malone, the inspiring colonel of the Wellingtons, was killed and only 70 of nearly 800 of his men remained in action. After dark the Otago Battalion and Wellington Mounted Rifles came up and the situation eased, though the Turks counter-attacked throughout the night. Early on the ninth Gurkhas and some South Lancashire men reached the crest higher up but were driven back. By the eleventh the Turks regained all but the foothills and the vision of victory faded. In a last effort the mounted rifles, Australians, and Indians on the twenty-first gained a toehold on Hill 60 to the north in bitter, costly fighting and enlarged it a week later; but the Suvla force failed in a parallel mission and at all points the Turks still overlooked the final line.

In mid-September the mounted rifles and infantry (less machine gunners and a few others) sailed for a rest at Lemnos. Of the mounted brigade there were only 249; of 677 Canterbury Mounted men (including reinforcements) only 28 sailed and 12 stayed behind; of the Wellington Mounted Regiment, 70 went, 14 stayed. The four infantry battalions each 1,000-strong when they landed and thrice reinforced since then, sailed in one small ship – 239 of the Canterburys, 130 of the Otagos, fewer than 100 of the Wellingtons, all looking like scarecrows. Rested, reinforced to about half strength, and smartened up, all units early in November returned to Anzac, to a snowstorm on the twenty-eighth, then winter gales with promise of more to come. But the promise was not fulfilled. Silently, skilfully, but with a sad sense of deserting their dead comrades, the men of Anzac and Suvla departed in mid-December, taking animals and guns and losing scarcely a man. As the last boats put to sea before dawn on the twentieth, mines exploded, many stores went up in flames, and the Turks fired wildly. This miracle was repeated at Helles on 9 January 1916 and the Gallipoli enterprise thus ended.

In all, 2,721 New Zealanders died, and 4,752 were wounded (some of whom later died). The British also suffered severe losses, and all who set foot on the peninsula paid in some way for the terrible hardships of that campaign. The adjective “untried” now disappeared from references to Australian and New Zealand troops and with it any doubt of their abilities. Their countries had come of age and were comrades in arms. Anzac Day in both countries commemorates the loss and also the gain.

The Senussi

The New Zealand Rifle Brigade (less two battalions) had meanwhile reached Egypt in November 1915 and was sent into the Egyptian desert to help defeat a Senussi invasion from Libya. The 1st Battalion fought two brisk but inexpensive actions south-west of Matruh as part of a mixed force (including British, Australians, and Indians), one on Christmas Day, the other on 23 January 1916. Both were successful and broke the back of the invasion. In mid-February the 1st Battalion rejoined the rest of the brigade at Moascar in the Suez Canal area.