Fritz X was the most common name for a German guided anti-ship glide bomb used during World War II. Fritz X was the world's first precision guided weapon ever deployed in combat, and the first to sink a ship in combat. Fritz X was a nickname used both by Allied and Luftwaffe personnel. Alternate names include Ruhrstahl SD 1400 X, Kramer X-1, PC 1400X or FX 1400 (the latter, along with the unguided PC 1400 ordnance's Fritz nickname, is the origin for the name "Fritz X"). Along with the USAAF's similar Azon weapon of the same period in World War II, it is one of the precursors of today's anti-ship missiles and precision-guided weapons.