Ptolemy I Soter rivals after Alexander's death. For example, Arrian's account of the fall of Thebes in 335 BC ("Anabasis" , a rare section of narrative explicitly attributed to Ptolemy by Arrian) shows several significant variations from the parallel account preserved in Diodorus Siculus (17.11–12), most notably in attributing a distinctly unheroic role in proceedings to Perdiccas. More recently, J. Roisman has argued that the case for Ptolemy's blackening of Perdiccas and others has been much exaggerated. Ptolemy personally sponsored the great mathematician Euclid. He found Euclid's seminal work, the "Elements", too difficult to study, so he asked if there were an easier
Political and military events in Scotland during the reign of David I of Scotland and England", a title which acknowledged the new Scoto-Northumbrian identity of David's realm. Political and military events in Scotland during the reign of David I Political and military events in Scotland during the reign of David I are the events which took place in Scotland during David I of Scotland's reign as King of Scots, from 1124 to 1153. When his brother Alexander I of Scotland died in 1124, David chose, with the backing of Henry I of England, to take the Kingdom of Alba for himself. David was forced to engage in warfare against his rival and