Alexander the Great's conquest of the Persian Empire was a defining moment in ancient history, and the Battle of Gaugamela was one of the most important battles in that campaign where Alexander the Great overthrew Darius III. The battle took place in 331 BCE near the city of Arbela in present-day Iraq, and it was fought between Alexander's army of Macedonian and Greek soldiers and Darius III's army of Persian soldiers. Darius III had a vast army of up to 200,000 soldiers, while Alexander had a force of around 47,000 soldiers. Despite being heavily outnumbered, Alexander's superior tactics and military leadership allowed him to defeat the Persian army and claim victory.
The battle was fought in an open plain, and Alexander's strategy was to draw the Persian army into a trap. He positioned his troops in a wedge-shaped formation, with his best soldiers in the center and weaker troops on the flanks. He also ordered his cavalry to charge at the Persian center, hoping to break through their lines and disrupt their formation. The Persian army, which was heavily reliant on its chariots and cavalry, was unable to respond effectively to Alexander's tactics, and they soon became disorganized that's why Alexander the Great overthrew Darius.
The battle was a decisive victory for Alexander, and it marked the end of the Achaemenid Empire. Darius III fled the battlefield and went into hiding, but he was eventually betrayed and murdered by his own men. Alexander went on to capture Babylon, Susa, and Persepolis, and he continued his conquest of the Persian Empire until his death in 323 BCE. The Battle of Gaugamela is remembered as one of Alexander's greatest victories and as a testament to his military prowess and leadership.