and crop failures could not be solved by the acquisition of more territory. At that point, the Empire fragmented into smaller units. Though it's often presumed that the collapse of the Roman Empire was a catastrophe for everyone involved, Tainter points out that it can be seen as a very rational preference of individuals at the time, many of whom were better off (all but the elite, presumably). Archeological evidence from human bones indicates that average nutrition improved after the collapse in many parts of the former Roman Empire. Average individuals may have benefited because they no longer had to invest in the burdensome complexity of empire. Tainter's view is supported by later studies which indicate that European men in the medieval period were taller than those of the Roman Empire. Average stature is a good indicator of nutrition and health. In Tainter's view, while invasions, crop failures, disease or environmental degradation may be the apparent causes of societal collapse, the ultimate cause is diminishing returns on investments in social complexity. Adrian Goldsworthy In The Complete Roman Army (2003) Adrian Goldsworthy, a British military historian, sees the causes of the collapse of the Roman Empire not in any 'decadence' in the make-up of the Roman legions, but in a combination of endless civil wars between factions of the Roman Army fighting for control of the Empire. This inevitably weakened the army and the society upon which it depended, making it less able to defend itself against the growing numbers of Rome's enemies. The army still remained a superior fighting instrument to its opponents, both civilized and barbarian; this is shown in the victories over Germanic tribes at the Battle of Strasbourg (357) and in its ability to hold the line against the Sassanid Persians throughout the 4th century. But, says Goldsworthy, "Weakening central authority, social and economic problems and, most of all, the continuing grind of civil wars eroded the political capacity to maintain the army at this level." Goldsworthy set out in greater detail his theory that recurring civil wars during the late fourth and early fifth centuries contributed to the fall of the West Roman Empire (395-476), in his book The Fall of the West: The Slow Death of the Roman Superpower (2009). Monocausal decay Disease William H. McNeill, a world historian, noted in chapter three of his book Plagues and Peoples (1976) that the Roman Empire suffered