The Battle of the Green Fork
Tywin Lannister won a battle, decisively, against the half of Robb StarkÔÇÖs army that was there to lose it.
Why it came to this
The Green Fork is one of the two halves of a single manoeuvre, and it makes no sense told on its own. When Robb Stark brought the North south to answer the arrest of his father, he faced the classic problem of the smaller, faster army against the larger one: Tywin LannisterÔÇÖs host stood between him and the Lannister forces besieging Riverrun, and if Robb tried to march past it he would be caught and destroyed, while if he tried to fight it head-on he would simply lose. So Robb did the thing that makes his brief war famous. He split his army.
He sent the greater part of his infantry ÔÇö the slow foot, the bulk of the levy ÔÇö south along the Green Fork under Roose Bolton, with orders to find Tywin, engage him, and above all fix him in place. Their job was not to win. Their job was to be an army in front of Tywin Lannister so convincingly that he did not notice the other, smaller, all-mounted half of RobbÔÇÖs host slipping around him through the crossings to fall on the force besieging Riverrun. The Green Fork was a feint conducted at the scale of a full battle, and the men fighting it were, in the coldest sense, expendable.
Among them, entirely against his will, was Tyrion Lannister. Captured and released earlier in the war, he had fallen in with a band of the mountain clans of the Vale ÔÇö wild, quarrelsome, spectacularly violent hill people whom he had bought with promises of weapons and plunder ÔÇö and had been delivered by his own father into the van of the Lannister host, in the most exposed position on the field, as a way of getting him killed with plausible deniability. The Green Fork is thus one of the very few battles in the story observed from the inside by someone who understood exactly how little his own side valued him.
The ground and the hosts
The battle was fought on open ground along the Green Fork of the Trident, the kind of broad country that suits a straightforward clash of two infantry-heavy hosts and offers no clever ground to either side. This was deliberate on nobodyÔÇÖs part; it was simply where the two armies met when BoltonÔÇÖs northmen came far enough south to be found.
Tywin LannisterÔÇÖs host was large, well-ordered, and commanded by the most feared soldier of his generation, with his brother Ser Kevan as his reliable second. Tywin arrayed it conventionally and well: a strong centre, cavalry on the wings, and ÔÇö the detail that mattered ÔÇö his weakest and least reliable troops, including the hill clans and the newly arrived Tyrion, placed on the left, where he expected them to break and where their breaking would do him the least harm.
Roose Bolton commanded the northern foot, and Bolton is the second key to reading this battle. He fought it the way he did everything, which is to say carefully, and with a close eye on the preservation of Roose Bolton. The northern host he led was substantial but it was, by design, the part of RobbÔÇÖs army that could be spent, and Bolton fought it in a manner consistent with knowing that.
How it was fought
It was a big, blunt, conventional battle, and Tywin won it clearly. The two hosts came together in the ordinary way and the Lannister strength and discipline told; the northern line was pushed and eventually broken, and by the end of the day Tywin Lannister held the field and had inflicted heavier losses than he took. On the plain accounting of who held the ground afterward, it was a solid Lannister victory.
The battleÔÇÖs most famous stretch is the least strategically important, and that is the point of how it is told. Tyrion, stuck in the van with his hill clansmen, survived by a combination of luck, the clansmenÔÇÖs ferocity, and the frank cowardice of ducking the worst of it ÔÇö he is knocked cold early and wakes to find the battle won, which is his own sardonic verdict on the whole affair. The mountain clans fought like the wild things they were and came away blooded, paid, and armed, which was the entire arrangement.
The thing that makes the Green Fork a hollow victory is not visible on the field at all. Tywin had beaten an army; he had not beaten Robb StarkÔÇÖs army, or at least not the part of it that could hurt him. While he was winning decisively along the Green Fork, the real blow was being struck elsewhere, and the news of it turned his victory to ash within a day or two. Bolton had done his job to the letter: he had presented Tywin with a battle worth winning, and the winning of it had cost Robb nothing he was not prepared to lose.
What it cost
It cost the North a large part of its infantry ÔÇö real men, really killed, in a battle their own king had sent them to fight as a distraction. This is the uncomfortable underside of Robb StarkÔÇÖs brilliance as a young commander: the manoeuvre that made his reputation was paid for by the deaths of the men in the half of the army that was never meant to win, and they died beating no one and holding nothing.
It cost Tywin Lannister something less tangible and more valuable: certainty. He had fought and won a full-scale battle against a Stark host and been made a fool of by it, because the host he beat was the decoy. For a man whose entire authority rests on never being outmanoeuvred, being outmanoeuvred by a boy of sixteen ÔÇö even a boy who spent other menÔÇÖs lives to do it ÔÇö was a wound to exactly the thing Tywin most needed intact.
For Tyrion it cost a great deal of fear and bought a great deal of information. He came out of the Green Fork alive, having watched his father try to spend him, and the knowledge of precisely where he stood in TywinÔÇÖs accounting shaped every dealing the two of them had for the rest of TywinÔÇÖs life.
What it changed
The Green ForkÔÇÖs importance is entirely relative to the Whispering Wood, which it made possible. Read alone it is a Lannister win; read as half of a plan it is the successful sacrifice that let Robb Stark catch and shatter the other Lannister army and take its commander. The two battles have to be held together, and held together they are one of the most elegant pieces of generalship in the whole saga.
It also introduced, quietly, two of the warÔÇÖs decisive players in their true colours. Roose Bolton is first seen properly here, husbanding his strength and fighting a battle whose purpose was to lose usefully ÔÇö a man whose care for the preservation of his own is exactly the quality that makes him so dangerous later, when the NorthÔÇÖs survival and Roose BoltonÔÇÖs survival stop pointing in the same direction. And Tyrion is shown the precise value his father places on him, which is a lesson he does not forget.
Strategically it confirmed that Robb Stark could not be beaten by conventional means, because he would not fight conventional battles when a clever one was available. It took the Lannisters most of the war and a broken guest-law to solve a problem that the Green Fork first showed them they had.
What became of it ÔÇö if an ending is written, it is here. Spoilers.
Tywin Lannister came away from the Green Fork with a victory that curdled almost at once, and he spent the following stretch of the war on the back foot, pulling his forces about the riverlands in response to a boy who kept beating him. He solved the Robb Stark problem in the end, but he solved it with a letter and a wedding rather than a battle, having concluded ÔÇö correctly, and to his lasting credit as a strategist and lasting infamy as a man ÔÇö that he could not solve it on a field.
Roose Bolton survived the Green Fork, as Roose Bolton survived most things, by making sure the cost fell on other men. The care he showed for his own strength here is the same care that eventually let him change sides at the decisive moment with an intact following to bring to the other table.
Tyrion Lannister survived by being knocked unconscious early and by the ferocity of the hill clansmen he had bought, and walked away with his life, his clan allies, and a clear-eyed understanding of his fatherÔÇÖs hopes for his longevity. The mountain clans got their weapons and their plunder and went home to the Vale richer and better armed than they had come.