‘I’ve seen all the building that is going on at Arnäs,’ replied Birger Brosa in a different tone of voice, keeping his voice low. He threw out his arms in a gesture that almost looked like surrender. ‘I’ve seen what you’re building, and I’m not foolish. You’re building up the Folkung power to be greater than ever, you’re building so that we will be lords of this realm. My brother Magnus and your brother Eskil have also told me about what you’re doing at Forsvik. Need I say more?’

‘No, not if you wish me to forgive you, uncle,’ replied Arn cautiously.

‘Good! Will you have ale?’

‘I would prefer not to. During these past days I’ve had enough ale to last me till Christmas.’

Birger Brosa gave him a scornful smile and stood up. He took two ale tankards over to the ale cask, filled them both, and placed one of them in front of Arn before he went back to his seat. He settled himself more comfortably among the sheepskins with one knee drawn up; there he balanced his tankard, as was his custom. He gazed at Arn in silence for a while, but his expression was friendly.

‘Tell me of the castle that you’re building,’ he said. ‘How does it look today, how will it look when Arnäs is finished, and how will it look after several years?’

‘It will take time to answer these questions,’ said Arn.

‘Nothing is more important for the jarl of the realm at this moment. We have plenty of time, and we are alone, with no one else within earshot,’ replied Birger Brosa. He grabbed his tankard and took several good swallows before he placed it back on his knee. Then he threw out his hands without causing the tankard even to wobble.

‘Today there is peace, and the union is between the Eriks and Folkungs,’ Arn began hesitantly. ‘The Sverkers are lying low, biding their time until King Knut is gone, and God willing, that will not happen for a long time yet. So I do not see a war taking place for many years.’

‘Then we think alike,’ said the jarl, nodding. ‘But what about after that? What will happen then?’

‘No one knows,’ said Arn. ‘But one thing I do know: at that time there will be a greater danger of war. That doesn’t mean that things will go badly for us. For if we now build fortresses that are sufficiently strong, during the peace that we now have, our strength may preserve the peace as well as a wise marriage does.’

‘True,’ said Birger Brosa with a nod. ‘But what is our weakness?’

‘We cannot engage a Danish army on the battlefield,’ Arn swiftly replied.

‘A Danish army? Why a Danish army?’ asked Birger Brosa, raising his eyebrows.

‘That is the only danger we face and hence the only problem worth fretting about,’ replied Arn. ‘Denmark is a great power, a power that resembles the Frankish kingdom more than us, and the Danes wage war in the same way that the Franks do. The Danes have laid waste to great sections of Saxony and won much territory, showing that they are able to defeat Saxon armies. When they’ve had enough of heading southward, or when they reach so far south that they can no longer keep their armies supplied, they may turn their attention to the north. And here we sit, a much easier quarry than Saxony. And in Roskilde sits Karl Sverkersson’s son, raised as a Dane, but still with an inherited right to our crown. He could become the Danes’ nominal king in our realm. That is how the situation looks if we try to imagine what might be the worst thing that might happen.’

Birger Brosa nodded pensively, almost as if acknowledging to himself that these were his darkest thoughts and he would have preferred to ignore them. In silence he drank more ale, expecting Arn also to remain silent until he received another question.

‘When can we defeat the Danes?’ Birger Brosa asked abruptly, speaking in a loud voice.

‘In five or six years, but it will cost us dearly. In ten years it would be easier,’ replied Arn with such confidence that Birger Brosa, who had expected a more lengthy explanation, was caught off guard.

‘Give me a more detailed explanation,’ he said after another long pause.

‘In five years King Knut may die,’ said Arn, swiftly raising his hand to prevent any interruption. ‘We don’t know that, and it’s a wicked thing to think, but wicked ideas also have to be tested. Then the Danish army will come here with a more or less eager Sverker Karlsson following behind. We have a hundred horsemen. Not the kind of horsemen that can counter a great Frankish or Danish army, but a hundred horsemen that can make their passage through our land a great misery. They never engage us in battle nor do they catch up with us, but we take their supplies, we kill their draft animals, we kill or wound a dozen Danes each day. We do our best to entice them to pursue us to Arnäs. There they are crushed in their encampment. That’s what would happen in five years, and the price would be great devastation from Skara and all the way north.’

‘And in ten years?’ asked Birger Brosa.

‘In ten years we defeat them on the battlefield after first plaguing them with our light cavalry for a month,’ replied Arn. ‘But to make this possible, you will also have to exert yourself and pay for a great many things that will make big holes in your silver coffers.’

‘Why should I do this? Why not King Knut?’ asked Birger Brosa, and for the first time clearly showed surprise during this harsh conversation.

‘Because you are a Folkung,’ replied Arn. ‘The power that I am starting to build does not belong to the realm; it belongs to the Folkungs. It’s true that I have sworn loyalty to Knut, and I will stand by my oath. Perhaps some day I will also swear loyalty to Erik jarl, but we don’t know that. Today we’re united with the Eriks. But tomorrow? Of that we know nothing. The only thing that’s certain is that we Folkungs will stick together, and we’re the only power that can hold the realm together.’

‘I think you have understood this even better than you know,’ said Birger Brosa. ‘I must tell you something at once that is for your ears alone. But tell me first what you think I should do, as jarl or as a Folkung.’

‘You must build a fortress on the western shore of Lake Vättern, perhaps at Lena where you already own a large estate. The Danes will come from Skåne when they enter Western Götaland. At Skara they can continue on a northerly route toward Arnäs or take the unprotected road past Skövde and up to Lake Vättern and the king’s Näs. They must be stopped at Lena, and I hope that you will take this upon yourself. Axevalla at Skara must also be fortified. We will have our warriors in three fortresses. And our horsemen can move back and forth between the three without allowing the enemy to attack us, preventing them from knowing where the next assault will occur. With three strong fortresses, one of which is impregnable, we will be secure.’

‘But Axevalla is a royal castle,’ objected Birger Brosa.

‘All the better for the sake of your own expenses,’ said Arn with a smile. ‘If I build up Arnäs and you do the same with Lena, you, in your position as jarl, shouldn’t have a hard time convincing Knut that the king ought to add his straw to the stack and fortify his own castle of Axevalla. He would do it as much for his own sake as for ours.’

‘I notice that you’ve begun to speak to me as if we were equals,’ said Birger Brosa, and for the first time he gave Arn a broad smile, which had always been a distinctive characteristic of his, ever since his youth.

‘Now it’s my turn to ask forgiveness, my uncle. I got carried away,’ replied Arn, bowing his head for a moment.

‘I too got carried away,’ replied Birger Brosa, still smiling. ‘But from now on I wish that you and I continue to speak with each other in this informal manner, except possibly when we attend the king’s council. But now to what I wanted to tell you of a great and difficult matter. Perhaps I would like to see Sverker Karlsson as our next king.’