Yet there were times when he missed the frozen plains of his homeland. Winter was a passing thing in his new lands, always with the promise of a return to green life. Though their nights could be bitter, the people of his new khanate had no concept of the endless, crushing cold that had shaped the Mongol people, the desolate high plains that had to be fought for every meal, with life and sudden death as the stakes. His heartland had groves of figs and fruit, rolling hills and rivers that flooded every few years and had not run dry in living memory.

His summer palace had been built to the same specification and measurements as Ogedai's in Karakorum – then carefully reduced in all dimensions. Chagatai was nowhere near the fool some believed him to be. No great khan would enjoy hearing of a building to rival his own and Chagatai was careful to remain a support rather than any kind of threat.

He heard his servant approaching along the marble corridor that led to the audience room over the river. Suntai's sole concession to the climate was wearing open sandals with iron studs that clacked and echoed long before he could be seen. Chagatai stood on the balcony, enjoying the sight of the ducks sweeping in to settle in the reed beds along the banks. Above them, a lone white-tailed eagle hung in perfect stillness, silent and deadly.

As Suntai entered, Chagatai turned and gestured to a bottle of arack on the table. Both men had developed a taste for the aniseed drink so popular among the Persian citizens. Chagatai turned back to the river as Suntai clinked the cups together and poured, adding a dash of water so that it whitened like mare's milk.

Chagatai accepted the cup without taking his eyes off the eagle over the river. He squinted against the setting sun as it stooped, dropping suddenly to the waters and rising again with a squirming fish in its claws. The ducks rose in mindless panic and Chagatai smiled. When the air cooled in the evenings, he found he had grown affectionate towards his new home. It was a fitting land for those who would come after him. Ogedai had been generous.

'You have heard the news,' Chagatai said. It was a statement rather than a question. Any message that reached his summer palace would have passed through Suntai's hands at some point.

Suntai nodded, content to wait to hear his master's mind. To those who did not know him, he looked like any other warrior, though one who had marked his cheeks and chin with heavy lines of knife scars as some did, removing the need to shave on campaign. Suntai was always grubby and his hair was thick with ancient, rancid oil. He scorned the Persian habits of bathing and he suffered worse than most with boils and spreading rashes. With his dark eyes and lean frame, he looked like a rough killer. In fact, the mind behind the carefully created image was sharper than the knives he carried hidden against his skin.

'I did not expect to lose another brother so soon,' Chagatai said softly. He emptied the cup down his throat and belched. 'Two are gone. Just two of us remain.'

'Master, we should not stand at a window to discuss such things. There are always ears to hear.'

Chagatai shrugged and gestured with his empty cup. Suntai walked with him, deftly snatching up the jug of arack as he passed the table. They sat facing each other at an ornate table of gold-inlaid black wood, once the property of a Persian king. It was not symbolism that placed it at the very centre of the room. Suntai knew they could not be overheard by the keenest listener with his ears pressed to the outer walls. He suspected Ogedai would have spies in the new summer palace, just as Suntai had placed them with Tsubodai and Ogedai, Khasar and Kachiun, all the senior men he could reach. Loyalty was a difficult game, but he loved it.

'I have reports of the fit suffered by the khan,' Suntai said. 'I cannot say how close he was to death without interviewing the shaman who tended him. He is not one of mine, unfortunately.'

'Nevertheless, I must be ready to move at the first messenger to come galloping in.' Despite the placing of the table, Chagatai was unable to resist glancing around to be sure no one could hear him and he leaned forward, his voice very low.

'It took forty-nine days for me to hear this, Suntai. It is not good enough. If I am to take the great khanate as my own, I must have better news and faster. The next time Ogedai falls, I want to be there before he is cold, do you understand?'

Suntai touched his forehead, mouth and heart with his fingertips in the Arab gesture of respect and obedience.

'Your will commands me, my lord. One of my closest servants was gored in a boar hunt. It has taken time to replace him in the great khan's retinue. However, I have two others ready for promotion to his personal staff. In just a few months, they will be part of his innermost councils.'

'Make it so, Suntai. There will be only one chance to take the reins. I do not want his weakling son gathering the tribes before I can act. Serve me well in this and you will rise with me. The nation of my father is too strong for a man who cannot command even his own body.'

Suntai smiled tightly, rubbing the ugly ridged skin of his cheeks. The instinct of years prevented him from agreeing with the treason, or even to nod his head. He had spent too long with spies and informants and he never spoke without carefully weighing the words. Chagatai was used to his silences and merely refilled the cups, adding the splash of water that took the edge off the bitterness.

'Let us drink to my brother Tolui,' Chagatai said.

Suntai looked closely at him, but there was real grief in his eyes. The khan's spymaster raised his cup and dipped his gaze.

'He would have made my father proud with such a sacrifice,' Chagatai went on. 'It was insane, but by the sky father, it was a glorious insanity.'

Suntai drank, aware that his lord had been drinking most of the day already. It showed in his bloodshot eyes and clumsy movements. In comparison, Suntai only sipped from his cup. He almost choked when Chagatai slapped him on the shoulder and laughed, spilling the white liquid across the lacquer.

'Family is everything, Suntai, never think that I forget that…' He trailed off, staring into memories for a time. 'But I was my father's choice to succeed him. There was a time when my destiny was written in stone and carved deep. Now, I must make it for myself, but it is nothing more than fulfilling the old man's dreams.'

'I understand, my lord,' Suntai said, refilling Chagatai's cup. 'It is a worthy aim.'

CHAPTER SIXTEEN

The rain could not last, Tsubodai was almost certain. The sheer force of it was astonishing, drumming across his tumans. The sky was a wall of black cloud and lightning flashed at irregular intervals, revealing the battlefield in stark images. Tsubodai would never have fought on such a day if the enemy had not moved into position in the darkness. It was a bold move, even for mounted horsemen armed much as his own warriors.

The Volga river was behind them. It had taken another year to secure the lands beyond the river, the second since leaving Karakorum. He had chosen to be thorough, to sting the great men, attacking their walled towns and cities on a wide front until they were forced to unite against him. In that way, his tumans could destroy them all, rather than spend many years hunting down each duke and minor noble, whatever they called themselves. For months, Tsubodai had seen strangers watching his columns from hilltops, but they vanished when challenged, disappearing back into the damp forests. It seemed their masters knew no loyalty to each other and for a time he had been forced to pick them off one by one. It was not enough. To cover the sort of ground he intended, he dared not leave a major army or city untouched. It was a complex web of terrain and information and it grew harder to manage with each passing month. His spearhead was widening further and further, his resources stretched. He needed more men.