There are 12 books in the The Beast Arises series. The newest book is The Beheading which came out in 2016.

2
Predator, Prey

Book cover of Predator, Prey
After centuries of peace, the Imperium is thrown into panic as human worlds everywhere are menaced by orks. In a relentless tide of slaughter, ork attack moons destroy planet after planet with gravity weapons of unstoppable power. On Terra, the High Lords are paralysed by the scale of the threat,…

3
The Emperor Expects

Book cover of The Emperor Expects
As ork ships lay waste to world after world, heading inexorably towards Terra, Imperial citizens despair. The High Lords become desperate to prove that victory is possible, no matter the cost. A massive Navy fleet is assembled - their mission to make a definitive strike against the orks at Port…

4
The Last Wall

Book cover of The Last Wall
Despite the Imperium’s best attempts to forestall the ork plague that is wrecking havoc in human space, an ork attack moon now hangs over Terra. 

Despite the Imperium’s best attempts to forestall the ork plague that is wrecking havoc in human space, an ork attack moon now hangs over Terra.…

5
Throneworld

Book cover of Throneworld
The Imperium's situation has never been more grim - an ork attack moon hangs over Terra, and ork armadas ravage human space. To make matters even worse, eldar strike at the heart of the Imperial Palace, forcing humanity's defenders to fight on two fronts at once. Though it seems nothing…

6
Echoes of the Long War

Book cover of Echoes of the Long War
Space Marines are forced to ally with erstwhile foes to combat the orks in the latest in this gripping galactic saga.

Paralysed by the continued ork invasion of Imperial space, the rulers of Terra continue to fight among themselves. Finally losing patience with the High Council, Koorland ousts the Lord…

7
The Hunt for Vulkan

Book cover of The Hunt for Vulkan
The Adeptus Astartes carry the battle to the orks' home world, led by a mighty armoured warrior of legend.

Tearing itself apart from within, the Imperium is still virtually powerless to resist the ork advance. When the Adeptus Mechanicus reveal they have discovered the orks’ point of origin, the Adeptus…

8
The Beast Must Die

Book cover of The Beast Must Die
The imperium has been brought to the edge of extinction by an ork invasion of unprecedented scale and depth. Piecemeal strikes againstthe invaders prove totally ineffective - for every ork fleet destroyed, five more appear. The only solution is to find and kill the orks' warlord - The Great Beast.…

9
Watchers in Death

Book cover of Watchers in Death
The attampt to hunt down and kill the orks' leader has ended in failure and catastrophe. The Imperium is reeling from the loss of so many beloved heroes, and the military forces of mankind have been reduced to taatters. Koorland now knows that brute force is not the answer -…

10
The Last Son of Dorn

Book cover of The Last Son of Dorn
Koorland, the last son of Dorn, finally confronts the Beast in battle.

The first attempt to attack the orks’ home world has failed, but the Imperium is not defeated yet. New, more flexible fighting teams of Adeptus Astartes have been assembled – the Death Watch. Allies from the Imperium’s past…

11
Shadow of Ullanor

Book cover of Shadow of Ullanor
The Imperium's attempts to defeat the ork menace seem doomed to failure; it is only a matter of time before the greenskins triumph, and mankind is wiped from the face of galactic map. Yet there is some cause for hope - the Imperial Fists Chapter is reformed, and a few…

12
The Beheading

Book cover of The Beheading
Despite the odds, the Imperium has triumphed. The orks have been defeated and the Great Beast is no more. Across the length and breadth of the galaxy, humankind celebrates its salvation, and relishes the prospect of a return of peace. But the war against the orks has riven the political…