What's the family name of the heroes in "Castlevania"?

The answer is: Belmont

The Belmont family marched into gaming history when Simon Belmont first picked up the Vampire Killer whip in the original "Castlevania." The development team at Konami wanted a name that sounded European and in Japan, the family was called "Belmondo." They allegedly drew inspiration from French actor Jean-Paul Belmondo, but somewhere in translation, it became "Belmont" for Western releases.

While the 1986 game was our introduction to the legendary family, their lineage and reputation as monster hunters goes back centuries. The Belmonts are an ancient line of knights from France who moved east to pursue their crusade against the forces of darkness. The earliest vampire hunter in the family that we meet is Leon Belmont, who was kicking vampire butt all the way in 1094.

Each Belmont inherited not just the family name but also their signature weapon, the Vampire Killer whip. The family has some mystical connection to their weapons, which explains why they're the only ones who can use their whip without it backfiring horribly. Other families like the Morris clan have taken up vampire-hunting duties when no Belmonts were around, but there's something special about that Belmont blood.