Should the Battle of Gaugamela be considered a last stand?
No. A “Last Stand” is usually with one force that is unable to retreat or unwilling to retreat and facing a hopelessly outnumbered force. Custers last stand where he was outnumbered and surrounded, cut off from escape is a good example. Bataan and Coregidor are two good examples from WW2 Even the Spartans Vs the Persians at the Battle of Thermopylae can be considered a Last Stand, because even though they could have retreated, they chose not to and fought to the last man. But in this Battle, Neither Alexander nor Darius were cut off, surrounded, or in any way forced into a Fight they could not win. This was a Battle between two Armies, one of which outnumbered the other (Some accounts say vastly outnumbered but there is evidence to the contrary). But the Battle was fought in the open and either side could have retreated. Darius’s army broke and he was forced to flee. Alexander wanted to persue but turned back to protect his flank and preserve his army.