Alexander earned the epithet "the Great" due to his unparalleled success as a military commander. He never lost a battle, despite typically being outnumbered. This was due to use of terrain, phalanx and cavalry tactics, bold strategy, and the fierce loyalty of his troops. The Macedonian phalanx, armed with the sarissa, a spear long, had been developed and perfected by Philip II through rigorous training, and Alexander used its speed and manoeuvrability to great effect against larger but more disparate Persian forces. Alexander also recognized the potential for disunity among his diverse army, which employed various languages and weapons. He overcame this by being personally involved in battle, in the manner of a Macedonian king.