Golden Era of Go
This era of go playing occurred in Japan in the mid-19th century, prior to the Meiji Restoration. Honinbo Shusaku and Honinbo Shuwa were leading players of the time. Shusaku's thirty game match against Ota Yuzo, his strongest opponent, marked the end of the golden age of Go in Japan.
Note:
Arguably, the golden era of Go from a Korean perspective may well be the current one, since 1990, with the rise and shine of Lee ChangHo and the immense popularity of Baduk in his slipstream. Also, international matches between Chinese, Korean and Japanese professionals and the gradual penetration in the West could justify calling today's era the golden one. However, the name is not commonly used this way.