At his words the boarding ramps at the front of each Leviathan slammed down like drawbridges, explosive barbs burying themselves into the rockcrete skirt of Tor Tartarus. A hailstorm of assault grenades drove any defenders back. Then whistles were blown and the first Imperial troops roared their war cries and charged.

Bendikt had given the Honour of Immolation, the glory of making up the first wave, to the penal camp who had worked hardest. The position was given to the ten thousand men and women of the Seventh Kallic Penitentiary.

Their war cry was St Burri’s Psalm of the Condemned.

Forgive us, oh Emperor,

We who go into the pit.

Beyond hope of redemption.

The slain in the grave

Cut off from your hand.

Grant us redemption.

Their charge was an act of suicide. None of them got to the end of their prayer. The Seventh Kallic Penitentiary were cut apart by a blinding salvo of las and hard round fire. A reeking mist of blood and viscera rose into the air, and from the eviscerated bodies sheets of blood slewed from the sides of the boarding ramps like waterfalls in the mountains, and stained the sea beneath red.

Next came the 17th Crone Penal Guard, then the 104th Scarus Sinners, both regiments charging forward as soon as they could be brought to the top of the boarding ramps.

Tens of thousands of penal legionnaires were torn apart by the withering defensive fire. The slaughter was shocking, even to members of the Commissariat who witnessed the bloodshed.

Priests and commissars drove the troops forward with a terrible mix of terror, encouragement, exhortation and example. Bodies fell so thick that they made hills of the dead such that the warriors following used them as sandbag barricades. Bit by bit the walls of dead crept forward like the high-water mark of a murderous tide.

After an hour, the wall of bodies had reached the end of the boarding ramps. At this moment ogryn shock troops were unleashed. Each carried a triple-barrelled ripper gun and an abla­tive shield. Marching behind the wall of iron, they held on under the torrent of close-quarters fire.

The metal began to smoke. The ogryns clung on until their shields glowed red. As their hands burned, the dumb brutes threw the shields down in pain and they died by the hundred.

But they had done their job. They had acted as cover for the entrenching squads who fanned out with shovels and tube charges in the rubble skirts of Tor Tartarus, scraping out foxholes and establishing points of defence.

In the opening hours of the battle, Bendikt threw waves of chaff at the enemy.

All previous attempts by the Imperial Navy to bomb the ­island had been driven back by a rising crescendo of flak and hard rounds, but now at last, as the weight of ordnance drove the defenders into their bunkers, Bendikt gave the Navy the go-ahead.