Before the start of the First World War in 1914, Canada was a nation still shy of a half-century in existence — a glorified colony of Britain with a regular army of just 3,000 soldiers.

The next four years would see a crisis over conscription, the introduction of a "temporary" income tax, and a tragic explosion in Halifax. There would be bloody battles fought at Ypres, Passchendaele, the Somme and Vimy Ridge.

And in many ways, Canada — then a country of a little more than seven million people — would come of age.

All told, almost 650,000 Canadians and Newfoundlanders (the province then still a British colony) served in the so-called "war to end all wars." More than one in 10 would not come home. Tens of thousands of others would come back to Canada deeply wounded in body or mind.

The sacrifice and effort of the war years, however, brought Canadians a newly found sense of national pride and earned the country a considerable amount of autonomy from Britain.

The dawn of war

In the summer of 1914, Canada was in the grips of depression and unemployment. The Prairies were undergoing their second consecutive summer of drought. However, public attention was shifting to Europe, where there was an appetite for war.

Austria-Hungary declared war on Serbia after the June 28 assassination of the Archduke Franz Ferdinand. Germany, an Austrian ally, invaded Belgium and declared war on France weeks later. That brought the British Empire — and Canada — into the fighting on Aug. 4.

Prime Minister Robert Borden called for a national mobilization effort to help the British war effort, and the first contingent of the Canadian Expeditionary Force arrived in Britain on Oct. 14, 1914. After months training in the U.K., the force was deemed ready for action by the spring of 1915.

The Battle of Ypres, which began in April of that year, was the first major set of battles engaging Canadian troops. And early on, those troops would be introduced to an insidious new weapon.

The Germans used chlorine gas against the Canadian First Division, turning the air to deadly poison. Despite sustaining 6,000 casualties and fighting to a stalemate, the Canadian lines did not break and the troops earned a reputation for courage.

During the Ypres battle, Canadian Lt.-Col. John McCrae was inspired to write the poem In Flanders Fields after seeing poppies growing beside a grave of a close friend who had died in battle.

The poem was a great inspiration in adopting the poppy as the symbol of remembrance in Canada, France, the U.S, Britain and other Commonwealth countries.

The bloody Somme

The ill-fated Battle of the Somme, one of the bloodiest battles in history, took place in the summer and fall of 1916.

Losses of life were heavy for the British, French and Canadian forces in combat along the Somme River.

The Royal Newfoundland Regiment took exceptionally heavy casualties. To this day, special commemorations take place in Newfoundland on July 1.

By the time the battle had ended in November, 24,000 Canadians had died. All around, the military stalemate of 1916 had cost two million lives on all sides.

Valour at Vimy Ridge

The Allies launched a new offensive in the spring of 1917 on a newly fortified German line of defence. The Canadian contribution came at Vimy Ridge, a strategic escarpment overlooking the Douai plain of France.

In previous battles, tens of thousands of French and British soldiers had died trying to take it back from Germany. Allied commanders believed the ridge to be impregnable.

The four-day fight that began April 9, 1917, cost Canada dearly — 3,600 Canadian soldiers died, another 5,000 were wounded. But the ridge was taken, much of it in the first day. The nation basked in the pride of succeeding where larger, more established armies had not.

The Canadian military went on to make strategic gains, but not without heavy loss of life — more than 9,000 soldiers died in the Battle of Hill 70 near the French city of Lens in August 1917.

Thousands more died in the driving rain on a muddy battlefield at Passchendaele in the fall. Canadian troops captured the ridge in Belgium in November, ending a gruelling Allied offensive that had begun on July 31. Canadians earned a total of nine Victoria Crosses for their courage.

With the continued heavy losses of life, there would come a cry for more troops to reinforce the tested Canadian forces in Europe.

The Military Service Act, which allowed for the draft of troops, became law in August. The conscription issue triggered a political crisis that left deep divisions between English and French Canada, but callups began in early 1918.

By time of the war's end, almost 125,000 Canadians had been drafted and 25,000 would serve overseas.

Tragedy in Halifax

A collision in Halifax Harbour on Dec. 6, 1917, led to the biggest man-made explosion in the world before the era of the atomic bomb.

The Mont-Blanc, a French munitions ship, was sailing towards the harbour when it collided with the Norwegian ship Imo on its way out. The blast levelled most of the city and sent shards of glass and burning debris flying for miles.

Thousands were left dead, blinded or homeless.

Back in Europe, the German forces were becoming increasingly desperate to end the war by breaking through the Allied lines. The offensives, however, failed to achieve the expected gaps and by mid-1918, the Allied Forces were back on the attack.

The period known as Canada's Hundred Days began with the Allied assault on the German lines at Amiens, France, on Aug. 8. The Allies advanced several kilometres on the battle's first day — labelled the "black day" for a German army now on the defensive.

With momentum on their side, Canadian forces notched a number of hard-won victories over the next few months. It all led up to the capture of the Belgian city of Mons in November.

A ceasefire was nearly complete in the early hours of Nov. 11, but the fighting raged right up to final minutes before it was to take effect at 11 a.m. Canadian Pte. George Lawrence Price was the last Canadian soldier to die, felled by a German sniper's bullet at 10:58 a.m.

Aftermath of war

The First World War had ended, and the losses on all sides were staggering. Ten million soldiers had died, while another 29 million were hurt or missing.

Yet despite its own heavy toll, Canada had taken a major step forward in its pursuit of achieving full nationhood. Nowhere was this more apparent than at the signing of the Versailles peace treaty in 1919.

For the first time, Canada was allowed its own seat at the table. It added its own signature, independent of Britain, to the document that formally ended the hostilities.

A country had arrived on the international stage.