Alexander's brothers?

Our knowledge of the early life of Alexander the Great is based upon very slender literary evidence. Arrian devotes only a few sentences to the years prior to Alexander's campaigns. Plutarch's coverage of Alexander's youth is also very condensed, and both he and Arrian rely almost exclusively upon pro-Alexander sources such as Ptolemy and Aristoboulos. The books of Curtius which deal with the early years of Alexander have been lost, and Diodorus' coverage is as usual very scanty. Justin's epitome of Trogus is among our longest and most comprehensive accounts, but it is often rhetorically unreliable and careless with details. Yet apart from occasional flashbacks and allusions in these sources and a few fragments of other historians, this evidence—heavily biased, meager, and unreliable as it is—comprises all we know concerning the first twenty years of Alexander's life.