What, exactly, makes a battle decisive?
To start with I looked at what is probably the earliest
definitive list I could find of decisive battles, from Fifteen Decisive Battles
of the Western World by Edward Creasy, which was first published, I believe in
the 1850’s. It is free from Amazon on a Kindle, incidentally, which makes it
even more suitable for this task.
Creasy’s list of decisive battles is instructive: Marathon,
Syracuse, Arbela, Metaurus, Teutoburger Wald, Chalons, Tours, Hastings,
Orleans, the Spanish Armada, Blenheim, Pultova, Saratoga, Valmy and Waterloo.
Now, I suppose that any list of battles claimed to be
decisive would be arguable, but perhaps more interesting are Creasy’s reasons
for choosing them. Firstly, he claims that it is not the size of the battle,
nor the casualties, that make this set decisive. Nor, he suggests are to be
considered battles which, although dramatic, had either limited effects (particularly
geographically) or ‘merely confirmed’ already noted trends. Thus Plataea is not
on his list because the trend noted at Marathon, of Greek military success over
the Persians, is, he argues, the decisive one. Hence also the absence of Zama
from his list and the presence of Valmy instead of other actions of the
Revolutionary Wars.
Now, of course, this is a highly debatable issue. Every
statement that Creasy makes could be disputed. I have discussed his ideas so much
simply because they give a starting point to trying to understand what we mean
as decisive. As I mentioned in a comment at the time, decisiveness seems to
work at many levels.
Firstly, I think there is what we might term ‘tactically
decisive’ battles. These are the ones with clear cut outcomes on the field.
Classically, of course, up to the twentieth century (more or less), a decisive
battle would be one where one side was left in control of the battlefield and
the other had fled.
In ancient Greece, for example, the victors would put up a
trophy, while the defeated would send a herald to ask for a truce while the
dead were properly buried. This was an established custom, and serious
repercussions could ensue if it was not followed. Of course, in some cases, it
was unclear as to who the victor might be, in which case both sides could set
up a trophy. But the dead were still buried.
The tactically decisive battle, however, may not actually
resolve anything. Marathon, for example, only increased the Persian determination
to invade Greece (or so Herodotus reports). It could also be argued that
neither Salamis nor Plataea actually achieved anything very much apart from a
local defeat of the Persians. Looked at from the perspective of, say, 360 BC,
you could argue that the Persians had, in fact, won. This victory would not be
a military one, per se, but that, by switching their money from one side to
another, they could achieve a balance of power in Greece which gave them access
to Greek mercenaries and otherwise kept the fractious cities from being too
annoying.
At the next level up we have what I suppose we could term ‘operationally
decisive’ battles. By this I mean battles which did, at least, terminate a
campaign. An example of this could well be the complex of actions which led to
Plataea and Salamis. These battles did, in fact, terminate the Persian invasion
of Greece, even if the Greco- Persian wars continued. Another example might be
El Alamein, which did at least (more or less) terminate the campaigns in the
Western Desert.
At the top level are what I am going to call ‘strategically
decisive’ or ‘politically decisive’ battles. These are the big ones, the ones
which cause the fall of nations, the transfer of territory and so on. Actually,
in that case, there do seem to be relatively few of them. Hasting, probably, is
one of them, although I believe that historians can see increasing Norman
influence in England significantly before that. Waterloo would be another good candidate,
although again, given that Napoleon had already fallen it could be argued that
it was simply a post-script to what had gone before. Similarly, while Bosworth was decisive in
terms of the switch from Plantagenet to Tudor dynasties, many historians today
simply regard it as an aberration, for the “Wars of the Roses” had already
finished and the only argument was who, exactly was to be king.
I would imagine that even the categories I have outlined
above would be as arguable as Creasy’s criteria for deciding upon which battles
were decisive. I suspect that the decisiveness of a battle depends more upon
the time frame in which you consider it, and your interests, than by any
objective criteria.
If you are interested in the rise and fall of dynasties, for
example, then both Hastings and Bosworth are decisive. If you have a broader
view history and tend to discount individual events, then, perhaps, Bosworth is
a mere hiccough in the development of English monarchy and nation. Perhaps it
is only because humanity likes to categorize things extensively that we land up
with these sorts of discussions. Ultimately, the answer to the question ‘Was
battle X decisive?’ depends on what you mean by ‘decisive’ and at what level
you are looking.
So, finally, to the specific example that Chris and I were
discussing. Was Solway Firth decisive? Well, obviously, at a tactical level, it
was. The Scots were effectively ambushed and trounced by a fairly motley array
of English borderers.
At a campaign or operational level, I think that the answer is that Solway
probably was decisive, given that the Scots Lords would not cross the border
for another go. Whether the demise of James V was a consequence of the defeat
is another question which, I suspect, history cannot answer.
Was Solway a strategically decisive battle? Probably not.
The Scots and English were still fighting a decade later; neither had been
knocked out nor been dealt a decisive blow. In fact, I think that few battles really count at this level of decisiveness.