Shōgun is a 1975 novel by James Clavell

James Clavell

James Clavell, born Charles Edmund DuMaresq Clavell was an Australian-born, British novelist, screenwriter, director and World War II veteran and prisoner of war...

. It is the first novel

Novel

A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....

 (by internal chronology) of the author's Asian Saga. A major bestseller, by 1990 the book had sold 15 million copies worldwide. Beginning in 1600 in feudal Japan

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

, some months before the critical Battle of Sekigahara

Battle of Sekigahara

The , popularly known as the , was a decisive battle on October 21, 1600 which cleared the path to the Shogunate for Tokugawa Ieyasu...

, it gives an account of the rise of the daimyo

Daimyo

is a generic term referring to the powerful territorial lords in pre-modern Japan who ruled most of the country from their vast, hereditary land holdings...

 "Toranaga" (based upon the actual Tokugawa Ieyasu

Tokugawa Ieyasu

 was the founder and first shogun of the Tokugawa shogunate of Japan , which ruled from the Battle of Sekigahara  in 1600 until the Meiji Restoration in 1868. Ieyasu seized power in 1600, received appointment as shogun in 1603, abdicated from office in 1605, but...

) of the Shogunate

Shogun

A was one of the hereditary military dictators of Japan from 1192 to 1867. In this period, the shoguns, or their shikken regents , were the de facto rulers of Japan though they were nominally appointed by the emperor...

, seen through the eyes of an English sailor whose fictional heroics are loosely based on William Adams

William Adams (sailor)

William Adams , also known in Japanese as Anjin-sama and Miura Anjin , was an English navigator who travelled to Japan and is believed to be the first Englishman ever to reach that country...

's exploits.
Japan in 1600 is a feudal country in a precarious peace.