One of the most acclaimed streaming series of recent memory, FX’s “Shōgun” was based on a 1975 novel by author James Clavell. That same book previously inspired a memorable 1980 TV miniseries that was also well-received - if your dad watched the History Channel in the 90s, you probably saw the gigantic VHS box set somewhere on his shelf. But what you might not have realized is that both the book and subsequent two miniseries were rooted in real Japanese history, and provide a solid, though fictionalized, chronicle of the formation of the actual Tokugawa Shogunate. So…