Ever since the Franco-Prussian War in 1870 to 1871,
the Germans recognized that they were
likely to face another war with France.
That was the war that allowed Germany to unify.
They humiliated France.
They were able to capture some very valuable territory
from France, in particular Alsace and Lorraine,
which is very mineral rich.
And so the Germans were plotting too, well,
what are we going to do if we get into another war with them?
At the same time, once France and Russia had this alliance,
Germany fully recognized if there is a war with France,
it's likely to not be just with France.
It's likely to be a two front war.
On the Western Front, they'll be in conflict with France.
And on the Eastern Front, they'll
be in conflict with Russia.
And so to deal with this eventuality--
this is all the scheming that Germany
did in the decades going up to World War
I-- they came up with the Schlieffen Plan.
And I'm sure I'm mispronouncing it.
Named for Alfred von Schlieffen, he
was chief of the German Empire's general staff
from 1891 to 1905.
And it was based on how do you deal with a two front war?
And the general ides here were that Russia
had a large and almost inexhaustible army.
But because it was so large it would take a long time for it
to mobilize.
And the Germans are actually able to approximate it
correctly because this is how long it
did take the Russians to mobilize
at the beginning of World War I. They estimated that it would
take them about six weeks.
So the Schlieffen Plan called for enough German troops
on the Eastern Front, initially, in order
to keep the Russians at bay.
But then the main fighting force of the Germans,
while the Russians are mobilizing,
is to go after France and try to essentially knock France out
of commission, so that they're not facing a two front
war anymore.
And then have those troops go back
to fight against the Russians.
And the way that they wanted to do it
is by rolling through Belgium in a wheel like pattern like this.
And the reason why they wanted to do this wheel like pattern
is that they correctly predicted that the French were
very eager to get this territory right over here.
And the French actually had a plan--
they called it Plan 17- for going
after Alsace and Lorraine.
It was an offensive plan.
And the view is if the French army is
going in that direction, if the German army
rolls through Belgium and is able to get them from the rear,
they could put the French army out of commission.
So in early August 1914, the Germans,
once they declared war on France and on Russia,
the Germans tried to put the Schlieffen Plan into action.
And they frankly, almost succeeded.
So through August and early September,
the Germans were able to essentially roll
through Belgium and keep the combined, mainly French forces,
but there was also some assistance from British,
to keep them on their heels.
And this happened all the way until early September
when they get near the Marne, or a little bit
past the Marne River in France.
And it was here that the Sixth French Army--
and when we talk about armies we're
talking about huge numbers of troops.
The Sixth French Army had over 200,000 troops in it.
When we're talking about the Battle of the Marne--
which I'm about to talk to you.
We're talking about the first Battle of the Marne.
We're talking about a battle that
involves two million troops.
So these are battles that are occurring on an epic scale.
Just each of these armies-- this army
or this one, or even the German armies-- we're
talking about tens to hundreds of thousands of troops.
In general, an army characterize you're
talking about over 50,000, 60,000 troops.
So what happens as you go to early September, especially
September 5, 1914, the Sixth French Army
recognizes a mistake that the First German Army made.
By trying to roll around like this,
they exposed their right flank.
So right over here would be the right flank of the German army.
And just as most mammals, our flanks
are our weak spot, that area between your ribs
and your hips, the same thing is true for armies.
The front of the army tends to be
where you have the strongest forces.
And then you have your supply routes going back.
So if you can outflank an army-- and that's
what a lot of military strategy is designed around--
you can hit an army in its weaker points.
So by September 5, the First German Army recognized this,
but it was too late.
By September 6, they were essentially
being confronted by the Sixth French Army.
And by essentially turning to meet them
they created an opening between them and the Second German
Army.
And that opening was able-- the French and the British
were able to take advantage of that to essentially put
the Germans on their heels after a month of advancing.
And so right over here, you have the various French armies.
And they were assisted by the British expeditionary force.
And so from the Battle of the Marne, which
was essentially, most historians would say, between September 6,
or September 5, September 6 and September 12,
they were able to put the Germans on the retreat.
The Germans retreated past the Aisne River.
And then once you get into November
and the end of the year of 1914, the Germans essentially
entrenched themselves.
They were literally building deep trenches
in northern France and a little bit of western Belgium.
And what I have right over here-- let
me see if I can draw it.
What I have right over here, what the boundaries are
eventually happened after the Germans
suffered, essentially, their first big defeat.
They had to retreat and they had to literally retrench.
And this is what the borders would then be like.
And these were literally trenches getting dug here.
This first stage of the war was hugely dynamic.
You had armies moving fairly rapidly
over a period of weeks and months.
But then once the Germans retrenched,
you have roughly this position being static for the next three
years and the famous trench warfare of the Western front
that you might have seen movies on.
And I want to emphasize this was a big deal.
The first Battle of the Marne-- sometimes
it's called the Miracle of the Marne--
if the French, with British help,
were not able to push the Germans back,
they might have accomplished the Schlieffen Plan
and actually maybe would have won World War I,
or at least been able to win the Western front fairly quickly.
And then been able to deal with the Russians
a little bit better.
But because of the Miracle at the Marne--
which was hugely bloody.
We're talking about 500,000 casualties on both sides.
We're talking 100,000 to 200,000 dead on both sides.
But because of that, that was able to hold off the Germans.
But it got the Western front into this ugly three year
long trench warfare.