Marth (マルス, Marusu?) is a character from Intelligent System's Fire Emblem series of video games. More specifically, he is the central protagonist and Lord-class character of the original game Fire Emblem: Ankoku Ryū to Hikari no Ken, the third game, Fire Emblem: Monshō no Nazo, and the upcoming remake Fire Emblem: Shadow Dragon.

Although Marth's Fire Emblem titles were released only in Japan, He has acquired more widespread international attention through his recurring appearances in Nintendo's Super Smash Bros. series of fighting games. The appearance of Marth and Roy sparked a greater level of Western interest in the Fire Emblem series, and it was in part because of this that Nintendo began releasing the games internationally beginning with the seventh title in the series.

Source: Wikipedia