Shogun was the head master of all samurai and the actual ruler of Japan during the samurai era from 12th century to 19th century.
There were some Shogun in Japanese history but I think the most famous and greatest one was Tokugawa Ieyasu.
When he was born Japan was in the warring states states period.
He finally reunited Japan and made this country peaceful.
Since he was respected, his grand son and his religious adviser planned to build the shrine where enshrins Ieyasu.
That's Nikko Toshogu.
It's the shrine and the grave of the greatest Shogun.
You can see details from my tour.
https://gowithguide.com/japan/tour/nikko-all-about-toshogu-area-nikko-3107
Ieyasu founded Edo shogunate. Edo was an old name of Tokyo.
So we can say the Shogun made the base of Tokyo.