Throughout ancient Egyptian history its military underwent many significant changes. During the Old Kingdom, a standing army was not kept but if there was a conflict, an army would be called and organized, composed of older, untrained men. During the First Intermediate Period, the core of the army consisted of house troops. This core was made up of conscripts (men who were drafted into the army) and was supplemented by troops of an allied kingdom.
Mercenaries from Nubia with their bows and arrows were also used. The same type of army was used during the Middle Kingdom. During the Second Intermediate Period, the core of the army was made up of house troops, who were the personal troops of the king, .supplemented by conscripts. During the Late Period, the army was basically a Greek mercenary unit.
The most important thing that changed throughout Egypt's history was the technology of the military. During the Pre-dynastic Period, the army used weapons such as spears, cudgels, clubs, throwing sticks, daggers, bows, maces, and shields. During the Old Kingdom, the quiver was used and the battle-axe with a semi-circular head was invented. During the Middle Kingdom, the scalloped axe-head battle-axe was invented. During the Second Intermediate Period the chariots, composite bow, and narrow axe-headed battle-axe were invented. Most importantly, during the New Kingdom, the scimitar or sickle sword and body armor was invented.
The ancient Egyptian army was organized differently throughout time. From the Old Kingdom through the New Kingdom, the main fighting units of the Egyptian army were organized into battalions. During the New Kingdom, they were organized into divisions named after principal gods. The Egyptian infantry was divided into regiments, very similar to the Greeks; and these were formed and distinguished according to the army they bore. They consisted of bowmen, spearmen, swordsmen, clubmen, slingers, and other corps, disciplined according to the rules of regular tactics. The regiment was divided into battalions and companies, each officer had his particular rank and command.
When you consider all of ancient Egypt's great military, the most notable among the Pharaohs were Ramesses, Pepi, Thutmose, and Ahmose. The most notable soldiers were the composite bowmen, remembered even by the Romans. The composite bow was introduced by the Hyksos who came from Asia with the technology. The bow, nearly twice as strong as a regular bow, was invented by the Semites. It was of a long, slender strip of bullhorn, with a wood beam on either sides of the horn. This made a very springy yet sturdy bow. The horn and wood was covered with a strip of bark so the archer could have a firm grip on the weapon. Composite bowmen usually wore light clothes and little if any armor in order to give them greater flexibility. The Pharaoh had a war helmet that was made of leather with small metal rings. It bulged out in the front and there was a backside to protect the Pharaoh from a sweeping attack of a sword.
The Egyptian chariot charged the enemy in an orderly line. After the initial volley of enemy arrows, the enemy line disbanded. Given the broken line, the chariots dispensed over the battlefield, crushing the fugitives beneath their wheels and trampling them under their horse's feet. Another piece of military equipment that had a great impact was introduced by Thutmose III. It was wagons drawn by oxen to transport boats for the crossing of the Euphrates, and afterwards oxcarts formed part of the equipment of the Egyptian army.
Throughout Egyptian history, the battleship remained unchanged. They were built of bundles of reeds lashed together to form a narrow, sharp-ended hull and coated with pitch. These ships were fitted with a bipod mast and a single, large square sail. The ships had more than twenty oars on each side with two or more steering oars. Features were added to war galleys to make them more efficient for battle. Elevated decks were added for archers and spearmen. Planks were fitted to the gunwales to protect the rowers. Some galleys also had a projecting ram positioned well above the water line, which may have been designed to crash through the gunwale of an enemy or to ride upon deck.
The Egyptians had involuntarily become a war machine from the New Kingdom all the way through the Late Period. Ancient Egypt became a well trained, respected military force. They conquered many people and at one time their empire stretched all the way to the Euphrates River.