Panerai was founded in 1860 in Florence by Giovanni Panerai (1825–1897). It later became the official supplier of the Royal Italian Navy and expanded to building precision instruments. The company is famous for its Radiomir and Luminor watches, notable for their use by Italian commando frogmen, who relied upon their Panerai wristwatches to execute the sinking of Allied naval vessels in WWII.
The Florence-based watchmaker produced wrist worn diving instruments and about 300 watches, all for the Italian Marina Militare, between 1938 and 1993. By that time, the company ceased to provide watches to the Marina Militare, as they were no longer cost-effective nor did they meet the naval specifications. It then moved to launch its products to the civilian market, but remained relatively obscure until the actor Sylvester Stallone spotted and bought a Panerai Luminor in a jewelry store in Rome in 1995 to wear during shooting of the film Daylight. Stallone ordered a small batch of such watches with his signature on the case back, called Slytech. He offered them as gifts to friends, including Arnold Schwarzenegger. The watch gained rapid popularity, and Officine Panerai was eventually taken over by Richemont in 1997.