Sword of Altaïr

Altaïr has a personal sword that he uses throughout Assassin's Creed, Assassin's Creed: Altaïr's Chronicles, and Assassin's Creed: Bloodlines. The blade's hilt is shaped like an eagle's wings, while the blade itself is both long and agile, making it a light and deadly weapon. The sword is apparently the weapon of choice for the guards at Masyaf and an all metal variation is available as a weapon in Assassin's Creed II.
Availability
Assassin's Creed: Altaïr's Chronicles

Altaïr acquires this sword from a wounded guard early in the game and keeps it through the entire story.
Assassin's Creed
Altaïr starts the game with the Syrian sword, with which he is very skilled with until Al Mualim demotes him to Novice for breaking all three tenets of The Creed and decreases his abilities greatly. During his progression back into the ranks, he starts of with a sword that looks like this but does not have a cross guard - it only has a similar handle and blade. After he assassinates four targets he gets the Sword of Altaïr. He uses this sword before he is given the Syrian sword back.
Assassin's Creed: Bloodlines
Altaïr still possesses his sword during the events after Assassin's Creed Bloodlines. In fact, the sword(s) can be found hung in Kantara Castle Great Hall ('The Bull' stage), as ornaments. During the game this is the only sword that can be used. In the beginning it's attack power is quite low and enemies have to be hit with it for multiple times to be killed. The sword and other weapons of Altaïr however can be upgraded by collecting Templar coins and then used to purchase upgrades.
Assassin's Creed II
Altaïr's sword is available in the Monteriggioni blacksmith for 50,000ƒ (or less if it had been renovated) after DNA Sequence 8. This sword is the most powerful melee weapon in the game, as all three stats are maxed out. It is interesting to note that the picture of the weapon's hilt in the blacksmith has a leather-wrapped hilt, however the weapon does not have this leather wrapping.

Trivia
- It is unknown why the sword is available from the Monteriggioni blacksmith since the sword (being Altaïr's personal weapon) should be more likely available once his armor was unlocked, however, a possible cause is that the sword could have been lost along with the Codex, found, and later sold off to the blacksmith.
- The sword in the game is shorter compared to the other longswords Ezio can use; the entire sword being only a little longer than the length of his arm. However, Altaïr's sword is the strongest weapon available.
- Strangely, Altaïr's sword is considered the best sword in the second game; in Assassin's Creed, the Syrian sword was the best sword; however, it is possible that Altaïr modified the sword using the apple, similar to his armor. This is also made further possible as Altaïr uses this weapon in Assassin's Creed: Bloodlines as opposed to the Syrian Sword.
- It is interesting to note that in later memory sequences of Assassin's Creed II, if the player has the sword equipped, it is quite possible to be knocked away from Ezio by Brute guards.
- There is a glitch in the Xbox 360 and PS3 version which automatically replaces this sword with the "Common Sword" in Ezio's inventory. To fix this, you'll have to go to the weapon room in the Villa Auditore and equip Altaïr's sword again.
- Interestingly enough, in the second game, the Sword of Altaïr which is the weakest weapon in the first game and the strongest in the second was placed in the same rack as the Old Syrian Sword which is the strongest weapon in the first game.