The number of people killed in the conflict is difficult to estimate; contemporary writers gave widely variable figures, and these are considered by modern historians to be gross exaggerations. Al-Mas'udi reported a "moderate" estimate of 500,000 casualties – though he added a clarification that this was "empty conjecture - rigorous calculation the amount slain is impossible" – and separately noted that 300,000 were killed at the battle of Basra. Al-Suli gave a figure of 1,500,000 dead, which was subsequently quoted by multiple sources, while Ibn al-Taqtaqi provided a high-end number of 2,500,000. Al-Tabari's "History" contains no comprehensive figures, but the author frequently noted the number of soldiers killed or injured in individual battles, with amounts ranging from hundreds to thousands.