that the reader cannot trust the basic arguments." He concluded that ancient authorities were well aware of lead poisoning and that it was not endemic in the Roman empire nor did it cause its fall. Additionally, Roman authors such as Pliny the Elder and Vitruvius recognised the toxicity of lead. Catastrophic collapse J. B. Bury J. B. Bury's History of the Later Roman Empire (1889/1923) challenged the prevailing "theory of moral decay" established by Gibbon as well as the classic "clash of Christianity vs. paganism" theory, citing the relative success of the Eastern Empire, which was resolutely Christian. He held that Gibbon's grand history, though epoch-making in its research and detail, was too monocausal. His main difference from Gibbon lay in his interpretation of facts, rather than disputing any facts. He made it clear that he felt that Gibbon's thesis concerning "moral decay" was viable—but incomplete. Bury's judgment was that: Bury held that a number of crises arose simultaneously: economic decline, Germanic expansion, depopulation of Italy, dependency on Germanic foederati for the military, the disastrous (though Bury believed unknowing) treason of Stilicho, loss of martial vigor, Aetius' murder, the lack of any leader to replace Aetius—a series of misfortunes which, in combination, proved catastrophic: Peter Heather Peter Heather, in his The Fall of the Roman Empire (2005), maintains the Roman imperial system with its sometimes violent imperial transitions and problematic communications notwithstanding, was in fairly good shape during the first, second, and part of the 3rd centuries. According to Heather, the first real indication of trouble was the emergence in Iran of the Sassanid Persian empire (226–651). In Heather's words: Heather goes on to state—in the tradition of Gibbon and Bury—that it took the Roman Empire about half a century to cope with the Sassanid threat, which it did by stripping the western provincial towns and cities of their regional taxation income. The resulting expansion of military forces in the Middle East was finally successful in stabilizing the frontiers with the Sassanids, but the reduction of real income in the provinces of the Empire led to two trends which, Heather says, had a negative long-term impact. First, the incentive for local officials to spend their time and money in the development of local infrastructure disappeared. Public buildings from the 4th century onward tended to be much more modest and funded from central budgets, as the regional taxes had dried up.