In 1860, Giovanni Panerai opened a watch store in Florence, Italy. This was followed in 1936 by the development of a diver's watch for special diving units at the request of the Italian Navy. The brand was highly acclaimed and subsequently remained a military secret and out of the gate until the end of the 1980s.
Panerai's first civilian version was introduced in 1993. Since 2005, Panerai has been actively developing its own caliber models.

https://www.panerai.com/jp/ja/home.html