Sword of Altaïr

Throughout his life as an Assassin, Altaïr Ibn-La'Ahad wielded a personal sword of significant power. The blade's guard was shaped like an eagle's wings, with the pommel in the shape of an eagle's head.

In the Italian Renaissance, Ezio Auditore da Firenze, a direct descendant of Altaïr, also made use of his ancestor's personal weapon.

Third Crusade
Altaïr made use of his personal sword throughout most of his early life as an Assassin, using it with great skill and ease during missions such as the Quest for the Chalice.

By 1191, he instead began making use of a Syrian sword with a curved blade and a golden hilt. However, this sword was taken from him after Al Mualim demoted him to Novice for breaking all three tenets of the Creed.

During his progression back into the higher ranks, Altaïr started off with a basic sword similar to his personal one, though it lacked a cross guard. After he assassinated the first four of his nine assigned targets, his personal sword was returned to him. He made use of it until the Syrian sword was granted to him again.

Renaissance
Ezio Auditore was able to purchase his ancestor's sword from the blacksmith of Monteriggioni, and made use of it when he fought Rodrigo Borgia in the Vault.

He continued to use it as he escaped the Vatican with his uncle Mario. During the Fall of Monteriggioni however, he did not have time to re-equip it, and it was lost in the rubble of the Villa Auditore, along with much of his armor and other weapons.

Some time after establishing his Assassins Guild in Rome, he was able to recover the sword again, and made use of it during the Siege of Viana.

Appearance

 * It is interesting to note that the picture at the Blacksmiths shows the weapon's hilt wrapped in leather, however, the weapon itself does not have any leather wrapping.
 * The swords appearance is slightly altered in Assassin's Creed II and Assassin's Creed: Brotherhood, with the handle turning from a bronzed color, to completely silver.
 * This sword is shorter compared to the other longswords Ezio can use, with the entire sword being only a little longer than the length of his arm. Despite this, Altaïr's sword is still the strongest weapon available.

Usage

 * The guards at Masyaf are seen wielding a sword similar to Altaïr's.
 * Oddly, in Assassin's Creed: Bloodlines, many if not all of the enemy guards can be seen wielding a sword similar to the sword of Altaïr.
 * Assassin Apprentices are able to use this sword once they reach the final rank of Assassino, however for them, it is called the "Assassin Sword."
 * During the memory "Follow The Money" in Assassin's Creed: Brotherhood, a guard draws and raises the Sword of Altaïr to threaten Egidio Troche. This is rather unusual, and unclear if intentional or rendered accidentally by the developers.
 * Later in the same memory, a Papal Guard is seen with the sword, or at least one very similar to it.

Others

 * Strangely, though Altaïr's sword is considered the best sword in Assassin's Creed II and Assassin's Creed: Brotherhood, in Assassin's Creed, the Syrian sword (which in Assassin's Creed II was among the cheapest weapons) was the best sword.
 * The sword of Altaïr can be found in the "The Bull" stage of Assassin's Creed: Bloodlines, as an ornament in the Kantara Castle's Great Hall.
 * After buying the sword of Altaïr, it may occasionally be randomly replaced with the common sword. To properly acquire it if this occurs, simply go to the Villa's weapon rack and re-equip it.
 * It is interesting to note that in later memory sequences, if the player has the sword equipped, it can possibly be knocked out of Ezio's hands by Brute guards, and even picked up by an NPC. It can, however, be re-equipped in the Villa.
 * It is unknown why the sword is available from the Monteriggioni blacksmith, since the sword (being Altaïr's personal weapon) would be assumed to be available together with his armor once it was unlocked.
 * The sword appears on a weapon rack in the Tiber Island headquarters once Ezio completes all five Assassin's Guild challenges, and can only be equipped from there.