Genghis let his mare have her head on the open plain, hitting full gallop so that the warm air rushed by him and sent his long, black hair streaming in the wind. He wore only a light tunic that left his arms bare, revealing a dense web of white scars. The trousers that gripped the mare’s flanks were old and dark with mutton fat, as were the soft boots in the stirrups. He carried no sword, though a leather bowcase rested behind his thigh and a small hunting quiver bounced on his shoulders, its leather strap running across his chest.

      The air was black with birds overhead, the noise of their wings clattering as hawks tore through them, bringing prey back to their masters. In the distance, three thousand warriors had formed an unbroken ring, riding slowly and driving every living thing before them. It would not be long before the centre was filled with marmots, deer, foxes, rats, wild dogs and a thousand other small animals. Genghis could see the ground was dark with them and he grinned in anticipation of the killing ahead. A deer ran bucking and snorting in panic through the circle and Genghis took it easily, sending a shaft into its chest behind the foreleg. The buck collapsed, kicking, and he turned to see if his brother Kachiun had witnessed the shot.

      There was little true sport in the circle hunt, though it helped to feed the tribes when meat was running low. Nevertheless, Genghis enjoyed it and awarded places at the centre to men he wished to honour. As well as Kachiun, Arslan was there, the first man to take an oath to him. The old swordsman was sixty years of age and knife-thin. He rode well, if stiffly, and Genghis saw him take a pigeon from the air as the bird flew overhead.

      The wrestler Tolui galloped across his vision, leaning low on the saddle to drop a fat marmot as it streaked across the grass in panic. A wolf came from a patch of long grass and made Tolui’s pony shy, almost unseating him. Genghis laughed as the massive warrior struggled upright. It was a good day and the circle was almost upon them. A hundred of his most valued officers raced here and there as the ground darkened into a solid stream of animals. They swarmed so thickly that more were crushed by hooves than spitted on killing shafts. The circle of riders closed until they stood shoulder to shoulder and the men in the middle emptied their quivers, enjoying themselves.

      Genghis spotted a mountain cat in the press and kicked his heels in after it. He saw Kachiun on the same run and was pleased when his brother wheeled away to leave him the shot. Both men were in their late thirties, strong and supremely fit. With the armies returning, they would take the nation into new lands and Genghis was glad of it.

      He had come back from the Chin capital worn out and racked by illness. It had taken almost a year for him to regain his health, but the weakness was now only a memory. As the end of summer approached, he felt his old strength and, with it, the desire to crush those who had dared to kill his men. He wanted his enemies proud and strong, so that he could cast them further down in his vengeance.

      Genghis reached for another arrow and his fingers closed on nothing, making him sigh. The boys and girls of the camps would now run in with hammers and knives to finish the slaughter and begin preparing the carcases for a great feast.

      The scouts for the khan had reported the armies of Khasar and Tsubodai only a few days’ ride away. His generals would be honoured with rice wine and black airag when they returned. Genghis wondered how his sons would have grown in the years apart. It was exciting to think of riding to war with Chagatai and Ogedai, taking new lands so that they too could be khans. He knew that Jochi was returning, but that was an old wound and he did not dwell on it. He had enjoyed peaceful years with his wives and young children, but if the sky father had a purpose for him, he knew it was not to spend his time quietly while the world slept.

      Genghis rode to Kachiun as his brother clapped Arslan on the shoulders. Between them, the ground was red with blood and fur, and boys darted almost under the hooves as they yelled and called to each other in excitement.

      ‘Did you see the great cat I brought down?’ Genghis said to the two men. ‘It took two arrows just to slow it.’

      ‘It was a fine kill,’ Kachiun shouted, his face glowing with sweat. One scrawny boy came too close to Kachiun’s stirrups as he spoke and he reached down to cuff the lad, knocking him sprawling, to the amusement of his companions.

      Arslan smiled as the little boy picked himself up and glared at the khan’s brother before racing off.

      ‘They are so young, this new generation,’ he said. ‘I can hardly remember being so small.’

      Genghis nodded. The children of the tribes would never know the fear of being hunted as he and his brothers had. Listening to their laughter and high-pitched voices, he could only wonder at what he had achieved. Just a few herdsmen still roamed the valleys and mountains of his homeland. He had gathered the rest and made them a nation under one