The Astra Militarum is often referred to as the 'Hammer of the Emperor' - the sheer amount of force that the Imperial Guard can bring to bear on the enemy is devastating, but is not as direct or as precise as their Space Marine allies, who are described as the 'Scalpel of the Emperor.' Supported by legions of heavy armour and thundering artillery, the Imperial Guard fight a never-ending war for the survival of Mankind in an unrelentingly hostile universe.

They also garrison major locations of strategic or cultural interest to the Imperium and are often found in defensive roles. The Astra Militarum are usually the first Imperial force to respond to a threat if a world's Planetary Defence Force (PDF) fails to suppress it. It is comprised of countless billions of men and women - hundreds of thousands of different regiments, supported by a vast array of light and heavy armoured vehicles that provide the Guard's primary offensive punch. They serve as the Imperium of Man's primary combat force and first line of defence from the myriad threats which endanger the existence of the Human race in the 41st Millennium. The Astra Militarum, also known as the Imperial GuardВ in colloquial Low Gothic, is the largest coherent fighting force in the galaxy. Imperial Reformation (Early 31st Millennium)

Imperial guard vs tau