Kongō Gumi was founded in 578. Don’t worry about doing the math. It began a century after the fall of the Roman Empire. So a really long time ago.
It operated for more than 1,400 years as an independent family business before becoming a subsidiary of Takamatsu Kensetsu in 2006. It continues to operate today, constructing, maintaining, and repairing Buddhist temples, using the same traditional tools and techniques passed down for centuries.