In the summer dusk, the encampment of the Mongols stretched for miles in every direction, the great gathering still dwarfed by the plain in the shadow of the black mountain. Ger tents speckled the landscape as far as the eye could see and around them thousands of cooking fires lit the ground. Beyond those, herds of ponies, goats, sheep and yaks stripped the ground of grass in their constant hunger. Each dawn saw them driven away to the river and good grazing before returning to the gers. Though Genghis guaranteed the peace, tension and suspicion grew each day. None there had seen such a host before and it was easy to feel hemmed in by the numbers. Insults imaginary and real were exchanged as all felt the pressure of living too close to warriors they did not know. In the evenings, there were many fights between the young men, despite the prohibition. Each dawn found one or two bodies of those who had tried to settle an old score or grudge. The tribes muttered among themselves while they waited to hear why they had been brought so far from their own lands.

      In the centre of the army of tents and carts stood the ger of Genghis himself, unlike anything seen before on the plains. Half as high again as the others, it was twice the width and built of stronger materials than the wicker lattice of the gers around it. The construction had proved too heavy to dismantle easily and was mounted on a wheeled cart drawn by eight oxen. As the night came, many hundreds of warriors directed their feet towards it, just to confirm what they had heard and to marvel.

      Inside, the great ger was lit with mutton-oil lamps, casting a warm glow over the inhabitants and making the air thick. The walls were hung with silk war banners, but Genghis disdained any show of wealth and sat on a rough wooden bench. His brothers lay sprawled on piled horse blankets and saddles, drinking and chatting idly.

      Before Genghis sat a nervous young warrior, still sweating from the long ride that had brought him amongst such a host. The men around the khan did not seem to be paying attention, but the messenger was aware that their hands were never far from their weapons. They did not seem tense or worried at his presence and he considered that their hands might always be near a blade. His people had made their decision and he hoped the elder khans knew what they were doing.

      ‘If you have finished your tea, I will hear the message,’ Genghis said.

      The messenger nodded, placing the shallow cup back on the floor at his feet. He swallowed his last gulp as he closed his eyes and recited, ‘These are the words of Barchuk, who is khan to the Uighurs.’

      The conversations and laughter around him died away as he spoke and he knew they were all listening. His nervousness grew.

      ‘It is with joy that I learned of your glory, my lord Genghis Khan. We had grown weary waiting for our people to know one another and rise. The sun has risen. The river is freed of ice. You are the gurkhan, the one who will lead us all. I will dedicate my strength and knowledge to you.’

      The messenger stopped and wiped sweat from his brow. When he opened his eyes, he saw that Genghis was looking at him quizzically and his stomach tightened in fear.

      ‘The words are very fine,’ Genghis said, ‘but where are the Uighurs? They have had a year to reach this place. If I have to fetch them …’ He left the threat dangling.

      The messenger spoke quickly. ‘My lord, it took months just to build the carts to travel. We have not moved from our lands in many generations. Five great temples had to be taken apart, stone by stone, each one numbered so that it could be built again. Our store of scrolls took a dozen carts by itself and cannot move quickly.’

      ‘You have writing?’ Genghis asked, sitting forward with interest.

      The messenger nodded without pride.

      ‘For many years now, lord. We have collected the writings of nations in the west, whenever they have allowed us to trade for them. Our khan is a man of great learning and has even copied works of the Chin and the Xi Xia.’

      ‘So I am to welcome scholars and teachers to this place?’ Genghis said. ‘Will you fight with scrolls?’

      The messenger coloured as the men in the ger chuckled.

      ‘There are four thousand warriors also, my lord. They will follow Barchuk wherever he leads them.’

      ‘They will follow me, or they will be left as flesh on the grass,’ Genghis replied. For a moment, the messenger could only stare, but then he dropped his eyes to the polished wooden floor and remained silent.

      Genghis stifled his irritation.

      ‘You have not said when they will come, these Uighur scholars,’ he said.

      ‘They could be only days behind me, lord. I left three moons ago and they were almost ready to leave. It cannot be long now, if you will have patience.’

      ‘For four thousand, I will wait,’ Genghis said softly, thinking. ‘You know the Chin writing?’

      ‘I do not have my letters, lord. My khan can read their words.’

      ‘Do these scrolls say how to take a city made of stone?’

      The messenger hesitated as he felt the sharp interest of the men around him.

      ‘I have not heard of anything like that, lord. The Chin write about philosophy, the words of the Buddha, Confucius and Lao Tzu. They do not write of war, or if they do, they have not allowed us to see those scrolls.’

      ‘Then they are of no use to me,’ Genghis snapped. ‘Get yourself a meal and be careful not to start a fight with