Alexander Senki (Japanese: アレクサンダー戦記, Hepburn: Arekusandā Senki, lit. "Alexander War Chronicle"), released in North America as Reign: The Conqueror and in Europe as Alexander the Great, is a Korean-Japanese anime first released in 1999. A re-imagination of the life of Alexander the Great based on the novel of the same name by Hiroshi Aramata, the series was produced by an international crew that drew from the resources of the worldwide animation community. Character designs and original designs for the show were conceived by Peter Chung (known for Æon Flux) while the show was written by Sadayuki Murai and directed by Yoshinori Kanemori. Most of the production work was handled by Korean animators.

In the original attempt at American distribution, the producers created a dub under the direction of veteran voice director Jack Fletcher. However, when the anime was picked up by Tokyopop and prepared for its 2003 release as Reign: The Conqueror, another dub was created. Still, Tokyopop retained the rights to the first four episodes of the series containing Fletcher's original dub, and used them for the first four episodes of the American release. It used the second dub for the remaining episodes. Only John DeMita would return to voice in the series under the alias Will Barrett, and would also take over the role of Alexander from Andrew Philpot.

There is also a theatrical version of Reign: The Conqueror, known as Alexander: The Movie in North America, which consists almost entirely of recut footage from the series, with the only new content being short opening and closing scenes. The movie covers the first ten episodes of the anime, ending with Alexander's victory over Darius and the Persian army.