British war correspondent Philip Gibbs wrote that Canadian soldiers "fought the Germans with a long, enduring, terrible, skilful patience”, while poet Robert Graves said they had the "worst reputation for acts of violence" against prisoners.

The Germans did fear Canadian troops in WWI, some from the stories that did leak out from German POWs. But much of this fear stemmed from the night-time trench raids. This was brutal, messy and savage close-quarters fighting, where entire dugouts of sleeping Germans would be burned or buried alive where they lay, with grenades or poison gas lobbed at them, and those who fled would be shot, clubbed to death or bayoneted. Britain encouraged all imperial and Dominion troops to conduct trench raids, but the Canadian troops were particularly adept in practising this type of warfare -- and continued to do so, even after other imperial units stopped.

In the lead up to the Battle of Vimy Ridge in 1917 (part of the Battle of Arras) -- the battle acclaimed in Canada as a defining moment in nationhood because they prevailed where none of the Allies did before -- trench raiders penetrated up to 1 km behind enemy lines, causing mayhem in the German ranks. Some raids had upwards of 900 men hurled into enemy trenches, nightly. During these mini-battles, tales would come out about German soldiers trying to surrender but getting shot instead out of anger, bloodlust or expediency. There are also cases where Canadian officers gave explicit orders to take no prisoners. Such behaviour on the front wasn't unique to Canadian troops, with other Allied troops committing similar actions at the time.

By 1918, the Canadian Corps had a reputation as an army of "no mercy" across Northern France. This was both a propaganda tool British and Canadian forces readily exploited and also reflected the sad reality that colonial and Dominion troops were often hurled into the first wave of attacks, and thus more likely to come into contact with large numbers of Germans wanting to surrender.

Like many nations at war, Canada's history of WWI tends to highlight the acts of valour, honour and self-sacrifice -- Ypres, Vimy Ridge, the Victoria Crosses earned -- because it suited Canada's concept of emerging nationhood and identity and casts it in its best light. But WWI was the war to end all wars, with some horrible deeds done to achieve victory. The less palatable acts tend to be glossed over or downplayed to preserve national honour. No country that fought in the hellish conditions of WWI was immune, Canada included.

Canada had sent 630,000 to war out of a population of only 8 million. It lost 61,000 war dead and 172,000 wounded, fighting for king and empire. In an act of autonomy from British control, Canada pushed for and earned a seat at Versailles and signed the 1919 treaty independently of Britain.

Sources:

Hopper, Tristin. "The forgotten ruthlessness of Canada's Great War soldiers". Article. National Post. Nov 12, 2018.

Morton, Desmond. "First World War (WWI)". Article. thecanadianencyclopedia.ca. August 5 2013.

The saying goes that the there are two sides to the story and the truth is somewhere in the middle.

Speaking strictly from the Australian perspective, there's a great deal of nationalist parochialism surrounding Australian military history, especially regarding the First World War that feeds into this "shock troop" trope.

In Australia's case part of what has recently been dubbed "Anzackery" stems from the fact that Australians saw themselves in the first part of the 20th century as Britons as well as Australians; part of an Empire founded on and maintained by an imperial prowess and reputation they themselves had relatively little part in establishing.

A resultant desire culturally for Australia to "prove itself" ended up converging with the ethno-nationalist pre-conceptions of C. E. W. Bean, the official war correspondent for the Australian Imperial Force who would later become Australia's official First World War Historian. Bean had preconcieved parochial biases and notions that complemented flattering reports from fellow war correspondents early in the conflict that made their way back to the Australian reader.

As time drew on there became little to no chance that this overly flattering narrative would be questioned by a nationalist public for whom such a history provided cultural validation, a boost to morale and a salve to the sacrifices the society was bearing both during and after the war.

So, we know where the hype (propogated later for a range of purposes) originally came from, at least from the Australian side of things.

Did the Germans buy it?

It probably depends on who you ask.

Would the Staff Officers at a very high level German Headquarters consider a couple of divisions of Australians to be any more worthy of fear than the same number of English, any more than similar movements within the French Army sectors? Possibly not. But that's not to suggest the Australians weren't feared or respected at all.

Especially by later in the war when the idea of anyone being "shock troops" was being popularised, there's very little evidence that Australians were considered so. But what they had developed was a well-deserved reputation for excellent small-unit battlefield cohesion and for being tough, and canny, opponents. They weren't hindered by adherence to some legacy military traditions in the same way that some parts of the British Army were, and by the war's later years, its mid-level and even senior leaders were almost exclusively field-experienced veterans - the AIF's successes in 1918 would reflect the benefits of that, even if the force was struggling to maintain its deployability in the face of voluntary manpower from Australia almost completely drying up.

The AIF had maintained their tactical and strategic cohesion in the face of appalling confrontations with the Germans throughout 1916, 1917 and 1918 that definitely weren't sideshows, regardless of how wary the Germans were of the French. Not only had the Australians maintained their cohesion (British historian Richard Holmes rated Dominion forces as qualitatively high in general terms) in the face of these efforts, their record throughout mid-late 1917, and in their defensive efforts during March-May 1918 spoke for themselves. So whilst there's no evidence to support this notion of Australian military superiority at the time, there's plenty that supports a notion of military proficiency and the due consideration from a sensible and intelligent adversary that comes with it.

No German officer operating at the Strategic level would've considered a force that would never exceed more than 5% of fighting manpower on one given front anything too scary. But German field officers who were further down in the weeds and were dealing with tactical and operational realities would've (and did) have different opinions.

Les Carlyon tells us of a German field officer who was of such a different opinion, complaining about being overrun three times in a single battle by a 'horde of drunken Australians" (he'd fled on the first two occasions). Carlyon likewise cites another German officer captured in the aftermath of Villers-Bretonneux as writing home that the "Australians and Canadians were the best troops the British have" - doubtless a hyperbolic anecdote borne of an individual's experience. In the same chapter of his book "The Great War" however, he also describes a German surrendering at Broodseinde who bemusedly describes the Australians as being "funny" men that rob and fight simultaneously - hardly a ringing endorsement of elite soldiery.

Carlyon is not the only Australian writer to sound cautionary notes about Australian "diggers" being super-soldiers of any kind. Jeffrey Grey quite explicitly points out "Individual skill and morale were no substitute for fire and movement. And the AIF had no monopoly on the latter."

It's highly unlikely that Erich Ludendorff was suffering nightmares about Albert Jacka or "Mad" Harry Murray when he made his famous statement about 8 August 1918 and what it meant for the German Army. Statements about the supposed quality of the 1st Australian Division attributed to other men like Herbert Plumer can be "strangely" difficult to track down (funnily enough so are similar "quotes" attributed to Montgomery and Rommel about the 9th Australian Division twenty odd years later - the Anzackery is real). And most tellingly of all, reliable evidence of Germans widely perceiving Australian soldiers as elite shock troops to be feared above all others are few and far between in most Australian sources. I can't speak for German sources, I have precious few of them... perhaps someone else can chime in on that score.

Did the average prudent German think Australian opponents were dangerous and worthy of respect? We have evidence to support that notion, yes.

Were Australians used very successfully and specifically for set piece assaults later in the war? Yes - Amiens, Hamel, and Mont St Quentin are demonstrable examples.

Do we have evidence that a typical German thought it likely that the typical Australian might fleece them of the watch their frau bought them as a going away gift? Definitely. We have attestations from Australian Officers at Villers Bretonneux of Germans coming surrendering with valuables already out and ready to hand over.

Did the Germans consider Australians elite shock troops that caused the wetting of much lederhosen? There are some Australian sources that will contend so, but the consensus from most academic historians does not appear to support this, even if Australians were used in a similar direct assault role, at a time when Dominion and British planning and combined arms deployment was particularly effective.

Grey, Jeffrey - A Military History of Australia 3rd Edition, 2008.

Carlyon, Les - The Great War, 2006.

Dennis, Peter et al - The Oxford Companion to Australian Military History 2nd Ed, 2008.