His wife's hand touched his arm and he realised he had been sitting with his eyes closed, silently rocking like the old ladies at prayer. He had to keep up a calm front, with so many eyes watching. They looked to him to protect them, but he felt helpless, lost. Winter did not stop the Mongol armies. If his brothers and cousins had trusted him, he could have put a force in the field to destroy the invaders, but instead they thought he schemed for power and ignored his letters and messengers. To be surrounded by such fools! It was hard to find peace, even on such a night.

'If He was not flesh, who was invited to the marriage in Cana? If He is not God, who turned the water into wine?'

The priest's voice echoed, rolling in a rhythm of its own that should have been comforting. They would not read the darker verses on the night of Christ's birth. Yaroslav did not know if the Mongol host would attack his cities of Vladimir and Moscow. Would they reach even Kiev? It was not so many years since they had struck so deep into the forests and tundra, killing at will and then vanishing again. There were many stories and legends of the fearsome 'Tartars'. It was all they had left behind the last time. Like a storm, they had struck and then vanished.

He had nothing that could stop them. Yaroslav began to wring his hands again, praying with all his heart that his city, his family might be spared. God had mercy, he knew. The Mongols had none.

Far away, thin shouts could be heard. The duke looked up. His wife was staring at him, her expression confused. He turned at the sound of running feet. Surely he would not be called out at this hour? Could his officers not handle one night without him, while he found solace in the Mother Church? He did not want to rise from the hard-won warmth of his seat. As he hesitated, more running steps could be heard as someone raced up the stairs to the bell tower. Yaroslav's stomach clenched in sudden terror. No, not here, not this night.

The bell began to toll above his head. Half the congregation looked up as if they could see it through the wooden beams. Yaroslav saw Father Dmitri walking towards him and stood quickly, struggling to master his fear. Before the priest could reach him, he bent down and spoke into his wife's ear.

'Take the children now. Take the carriage to the barracks, for your life. Find Konstantin; he will be there, with my horses. Get out of the city. I will come when I can.'

His wife was white-faced with terror, but she did not hesitate as she gathered his daughters and sons, herding them like sleepy geese. Duke Yaroslav was already moving, leaving his pew and striding down the central aisle. All eyes were on him as Father Dmitri caught up with the duke and dared to take his arm. The priest's voice was a harsh whisper.

'Is it an attack? The Tartars? Can you hold the city?'

Duke Yaroslav stopped suddenly, so that the elderly man stumbled into him. On another night, he might have had the priest whipped for his insolence. Yet he would not lie in the presence of the born Christ.

'If they are here, I cannot hold them, father, no. Look to your flock. I must save my own family.'

The priest fell back as if he had been struck, his mouth open in horror. Above their heads, the bell tolled on, calling despair across the city and the snow. The duke could hear screaming in the distance as he raced outside, his riding boots skidding on the icy cobbles. His family's coach was already moving, a black shape slipping into the darkness with the driver's whip-crack echoing on either side. He could hear his son's high voice fading into the distance, unaware of the danger as only a child can be.

Snow had begun to fall again and Yaroslav shivered as he stood there, his mind racing. For months he had heard reports of the Mongol atrocities. The city of Riazan had been reduced to smoking rubble, with wild animals tearing at bodies in the streets. He had ridden there himself with just a few of his guards and two of them had vomited into the snow at what they saw. They had been hard men, used to death, but what they had encountered was utter desolation, on a scale they had never known. This was an enemy with no concept of honour, who fought wars and destroyed cities to crush the will of an enemy. The duke stepped towards the snorting mount of his aide. It was a stallion, uncut, fast and black as night.

'Dismount,' he snapped. 'Return to the barracks on foot.'

'Yes, your grace,' the man said immediately, swinging his leg over and jumping down to the snow.

As the duke mounted in his place, finding the saddle still warm, the aide stood back and saluted. Yaroslav didn't look at him, already turning the animal and digging in his heels. The hooves clattered on the stone road as he trotted away. He could not gallop on the ice without risking a fall that could kill both him and the horse. He heard shouting voices nearby and then a single clash of steel on steel, a sword blow that carried in the frozen air from God alone knew how far away.

Around him, the sleeping city was waking up. Candles and lamps appeared in the windows and swung in the hands of men as they came out to stand in the street and shout questions to each other. None of them knew anything. More than once, they stumbled and fell as they tried to avoid the black horse and its rider.

The barracks were not far away. He half-expected to see his family's coach up ahead. The driver could force his horses to more speed, held steady by the weight of the carriage and those within. Duke Yaroslav prayed under his breath, asking the innocent virgin to take care of his little ones. He could not hold the city against the wolves that came in the snow. All he could do was escape. He told himself it was the correct tactical decision, but the shame of it burned him even against the cold.

As he rode, he ignored the voices calling behind him. There would be few survivors, not now the enemy had come in the depths of winter. No one could have expected it, he told himself. He had gathered his main army near Kiev, ready for the spring. They sat in a winter camp behind vast wooden palisades, almost three hundred miles to the south-west. He had just two thousand men in Moscow and they were not his best troops. Many were injured soldiers wintering in the comfort of the city rather than the army camps, where dysentery and cholera were a constant threat. The duke hardened his heart to their fate. They had to fight, to give him time to get free. He could only hope that the Mongol army had not yet blocked the roads out of the city. One of them must still be open, for his family.

Moonlight gleamed through the falling snow above him as he crossed a wooden bridge, the frozen Moskva river below. He glanced at it as he clattered over the ancient wood and stiffened in the saddle at the sight of the white river covered with horses and men. They were already spreading onto the banks like spilt blood, black in the night. He could hear more screaming as they tore into homes near the river. He put his head down and rode on, drawing the ornate dress sword on his hip. In terror, he saw dark figures clambering over the wooden bridge railings: two, no four, men. They had heard his horse, and as he saw them, something buzzed by his face, too fast even to flinch from it. He hoped the black horse made a difficult target and dug in his heels again, suddenly heedless of the slippery ground. A man loomed up on his right flank and Yaroslav kicked, feeling a spike of pain up his leg as the impact twisted his knee. The man fell away in silence, his chest crushed from the blow. The duke was through then, the white road opening before him as the bridge came to an end.

He felt the arrow strike as a shudder in his mount. The animal whinnied in pain, snorting harder and harder with every step. The gallop slowed and Yaroslav kicked and leaned forward, trying for the last burst of speed. His hands had held reins from a young age and he could almost feel the life drain out of the stallion as it struggled on, panic and duty keeping it going. He rounded a corner, leaving the bridge behind, but the animal's great heart could take him no further. The stallion went down hard, without warning, the front legs collapsing. Yaroslav tumbled, tucking in his head and trying to roll as he hit. Even with the snow, the ground was like iron and he lay winded and stunned, knowing he had somehow to regain his feet before they came looking. Dazed and helpless, he struggled up, wincing as his knee crackled and shifted under him. He would not cry out. He could hear their guttural voices just around the corner.