(3rd Person POV)
The Stormlands were bloodied but now fully united after the brutal victories at Summerhall. Robert Baratheon wasted no time after this and marched his banners west, towards the Reach. Robert had already discussed this with his brother Stannis, and they came up with the plan to have Stannis hold Storm's End. They counted on the incompetence of someone in particular to take the bait they had laid out. Everyone wanted to have a castle and city like Storm's End, so it stood to reason that it would be desired and targeted during the war. To get the situation they both wanted, Robert had to do his part as well.
He took his banners west towards Ashford. The town, sworn to Highgarden, was a loyalist ground in this war. Knowing this, the Reach, which had started to call its banners, was planning on marching east to meet Robert and the Stormlands' forces. But the Reach was far larger, and because they hadn't called their banners as soon as the Stormlands had, they were at a considerable disadvantage. They would never reach Ashford in time. However, Randyll Tarly had followed the political landscape and knew that they would have to be ready and called his banners sooner as well. Instead of waiting for the primary Reach host under Mace Tyrell, he instead marched north-east, towards Ashford, planning to ambush Robert and his forces.
Thinking that Robert meant to either snatch Ashford as a shield for his western flank or meet the Reach's vanguard head‑on before they could mass their full strength, Randyll and his forces had left. However, the strategically apt mind of Tarly couldn't comprehend the long planning that Robert and Stannis had in store, and what would have otherwise resulted in a brilliant move could only turn into a big mistake.
Robert, in truth, had no intention of winning a grand victory at Ashford. He never planned to take Ashford at all, since he had momentum and wouldn't sacrifice that for an inconsequential outpost like Ashford. His true aim was brutal and straightforward.
Robert split his forces before reaching Ashford, sending a second group northward to await him while he rode into battle with a smaller host. This served two purposes. On one hand, it would give Randyll Tarly a false sense of security, and after the battle, they would send false information back to King's Landing, allowing Robert and his host to surprise the loyalists with higher numbers.
At dawn, the two small armies met in the wet and cold mud around Ashford field. Randyll, the cold and disciplined warrior strategist, brought his van forward in perfect formation. He targeted what he saw as weak points in Stormland's army. Again, this was a calculated move on Robert's part, since he placed himself in the 'weak' areas.
He towered in his green steel and awaited the start of the battle. Seeing the charge of the Tarly van, he roared at his men to charge forward. The two forces met one another on the rather unsuitable terrain. Robert didn't care about positioning this time, as his plan was different from before. He had his forces position themselves behind him, spearheading through the Tarly's men and cutting deep into enemy lines. This would be atrocious if they planned on winning the battle the traditional way. Thankfully, they didn't. Now, the Stormland forces were right in the centre of the Tully army and were attacked on all sides.
However, Robert was now right in front of Randyll Tarly himself. Just as he wanted.
He leapt from his horse to meet him man to man. But Randyll didn't care about a duel. He ordered his soldiers to shoot Robert with arrows and take him down. Arrows flew through the air, hitting Robert's armour and aiming to strike between the protective plating. Robert, on the other hand, didn't care bout that. He stormed forward, swinging his warhammer through the air and killing any brave young soldier who thought he could end the war prematurely. How foolish they all were.
Robert's warhammer struck the armoured chests with full force, bending them and crushing the thorax of the man. He was dead before he hit the ground. Several arrows hit his armour, and very few lucky ones managed to cut into his flesh, hoping to put an end to the monster's madness. But it wouldn't be. Robert moved forward, only forward and crushed all who stood in his way... quite literally in fact.
Seeing that there might not be any better option than to swarm him, Randyll ordered his men to focus on Robert. However, that wasn't a very good idea either, since the men Robert had with him were capable soldiers. So the middle ground had to be taken. Again, the soldiers underestimated the monster that Robert truly was, and the effect it had on an average soldier's mind to see the 7-foot beast waltz through swathes of men. So eventually, no one dared to attack him on their own again, and they retreated rather than advanced.
"Come on, Randyll Tarly! Fight me, you smart cunt!"
Seeing the challenge as a means to hide, the soldiers stopped attacking and instead looked at their Lord. The situation was dire for Randyll, but he knew that he could either order a retreat right here and lose a lot of face or take the challenge and end Robert and maybe gain a lot of fame and glory for it. But who was he kidding? There was no way he could ever hope to do either. Robert was here for him and only him, and he wouldn't let him leave. So, the Lord of Horn Hill took his Valyrian Sword and walked forward.
"Very well, Lord Bar--"
But Robert wasn't there for a chat; he was there to kill the man. So he attacked right away.
The duel was fierce for Tarly. His blade struck again and again against Robert's hammer, which appeared in front of him out of nowhere. And while Robert had inhumane strength and speed, Randyll had the superior weapon. The storm given flesh, that was Robert, battered through the precise attacks and used sheer might to overwhelm Tarly. It wasn't a fight at all, and more like a show Robert put on for his men and the Reaches.
Robert moved forward with speed, bellying the weight of his size and armour and struck out against Tarly's shield and guard alike. With a single punch, Robert disarmed Tarly. The Lord of Horn Hill had no time to be surprised as Robert punched him in the face.
"Urgh..." Randyll groaned, disoriented and in pain.
"I am glad that you chose to engage me in a fight, rather than throw all your men at me. It made all of this far quicker," Robert said, as he stood above the Reach man.
"You and your men will die... This was a strategically bad move. No matter whether I live, you will most certainly die. Lord Tyrell is on his way here already."
Randyll held his face, which was bleeding heavily. He knew that he might not make it, but he did what he had to do to try to stay alive. Used as a hostage, he would survive. But he knew Robert badly.
"I know. But my goal was never to win this battle. You were my target. You and... your sword," Robert revealed.
Randyll suddenly understood that he wouldn't make it out alive. Robert didn't care about fighting the Reach here; he was only putting in a short stop before meeting up with his northern allies. Again, a misconception on his part. Because Robert had slightly different plans than that.
"You won't make it out... Mace Tyrell--"
"Let that be my problem to worry about. Farewell, Randyll Tarly of Horn Hill."
The dented and cut warhammer descended from the air and crashed into Lord Randyll Tarly with a blow so powerful that it split his helmet and skull at once, and even caused the ground to crater. In the silence that followed, Robert grabbed Heartsbane, the two-handed Valyrian steel greatsword of House Tarly, from the corpse's side and raised it high for all to see.
"""WHHOOOOOOOAAAAAAAHHHHHH!!!"""
His men roared, and so did Robert.
The Reach men faltered without their commander and at the sight of the display. Robert gave the signal and rushed to his horse, making a retreat right through the stunted Reach soldiers. And just in time as well. Because not even a full hour after the duel between the two Lords, horns sounded from the west: Mace Tyrell and the bulk of the Reach forces had arrived at last.
.
What he found was not the proud Randyll Tarly, but only broken corpses of animals and men, scattered dead, and the absence of Robert Baratheon. A lot of banners of Horn Hill lay trampled in the mud, and while not all of the soldiers were killed, it was what lay in the centre that shook everyone to their core. Randyll's body lay there in a hideous way. His helmet looked like the shell of a cracked egg, if one had used a hammer to crack the egg. The blood and brain matter were scattered across a wide area, painting a wretched picture.
Mace reined in his horse and stared, aghast, at the sight. Fury and disbelief crossed his mind. How could the most brilliant warrior of the Reach have been killed so swiftly and so brutally? How could Robert Baratheon, barely more than a boy, have carved his way through proud Rose Knights' ranks and slain Randyll before the main host even made it there?
"My Lord, it appears that we are too late."
"You don't say!" Mace shot back.
"I..."
"Where is Robert Barahteon? Where did that rat go?!" Mace yelled.
His stout appearance made him look a bit ridiculous and caused him trouble while riding. Thankfully, he had a strong horse, but the armour was still a bit tight. He was too angry to bother about that, though.
"They left north, my Lord. Most likely to meet with the hosts of the North and the Vale. Shall we follow them?"
Mace thought about it hard for a moment.
"If I may, my Lord. We should definitely pursue."
"I agree, Lord Tyrell. If we let this moment pass, Lord Tarly may have died in vain."
"Killing Robert Baratheon is of the utmost importance. Once he dies, the rebellion dies as well."
Around him, his captains and fellow Lords muttered that they should pursue the rebel stag at once, strike down his fleeing army, which clearly had their tails between their legs, before it could join the Northmen and the men of the Vale. But the Lord of Highgarden, swollen with pride and eager for the laurels of an easy victory, would not hear of it. As hilarious as it was, his thought process was once again wrong.
"No," he declared, "From what I have been told, the number of soldiers Robert Baratheon has now after the... glorious sacrifice that Lord Tarly made, is so few, that he will be easy picking. However, that also makes him faster than us, since we are a far larger host. So instead, we shall march east and destroy Storm's End and its foundations. The stag will return to find his den full of roses."
"But, my Lord, a siege might take too long. Lord Redwyne is on his way there already, not doubt, but in the meantime, Robert Baratheon may make it to the northern rebels. I believe this would be the wrong choice, strategically speaking."
"Oh? And you think that this was the right decision?" Mace said, waving his hands around.
"No, my Lord, but--"
"Enough. We shall do twofold. Send a group of 500 of our best knights to pursue Robert Baratheon and his men. Their morale is already weak, and we will ensure that it stays that way. If we are lucky enough to catch them, then all the better, but if we aren't, then I want our army to have already laid siege to Storm's End. And that's what we shall do."
"As you command, Lord Tyrell."
And so, while Robert moved north to join the bulk of the Stormland forces, Mace Tyrell led the large force of almost 90'000 knights and men-at-arms of the Reach to Storm's End, where they laid the largest and most prosperous city under a siege that would last close to a year.
.
.
(Stannis POV)
"Lord Stannis, a raven arrived," Mary says as she enters the room.
"From who?" I ask, looking up from my papers.
"Lord Robert, my Lord."
I take the letter and look at her.
"What is it, my Lord?"
"Have you eaten yet?" I ask.
"Don't you worry about--"
"I asked you a question, Mary."
"I will find the time to eat later, my Lord."
"You will go and eat."
"Bu--"
"Now!"
"...Very well."
I open the letter and read through it. I feel my shoulders relax after finishing. I wasn't aware that I was so tense. It seems Robert continues to do the impossible. Knowingly walking into their trap, just so he can take the ancestral sword of House Tarly, is not only reckless, it's...
"URGH, he makes me lose all my control."
However, this is good. This is better than good. He killed Randyll Tarly, a major threat in this war. Robert knew that should Randyll Tarly survive, he might convince Mace Tyrell to pursue them instead of laying siege to Storm's End. But Robert and I want to have them lay siege to us. There is no simpler and more effective way to remove the largest part of the loyalist army from the war.
So, Randyll Tarly had to die, and now that he did... we will be besieged any day now. So the time has come. A few very tense months are ahead of us. Better prove my brother's trust right. Can't go weak, now that he's outside, going through gore, mud and blood for victory. I shall not fall.