Tanegashima Tokiuji, Tadatoki's father, established a channel of communication to
Kinai (central Japan). In the 1460s the population of Tanegashima, Yakushima and Kuchierabu converted en masse to the Hokke sect of
Nichiren Buddhism. This established a firm link to
Honnō-ji of
Kyoto and
Honkōji of
Settsu Province, the sect's strongholds. Historical sources show that gifts dedicated to Honnō-ji by Tanegashima Tokiuji included Chinese and South Asian products such as silk fabric and pepper. In addition to Buddhist monks, craftsmen were moved from Kinai to Tanegashima. The heads of the Tanegashima clan personally visited Kinai and developed a network of contacts. Using this network, Tanegashima Shigetoki served as an intermediary between the imperial court and the Sōshū branch of the Shimazu clan, who later re-unified the Shimazu clan. Tanegashima Island functioned as a relay station of one of the main routes of Chinese trade that connected
Sakai to
Ningbo. The Tanegashima clan cooperated with the
Hosokawa clan, one of two powers who controlled Chinese trade. Tanegashima also engaged in trade with
Okinawa-centered
kingdom of Ryūkyū, which is attested by some letters given to Tanegashima by Ryūkyū in the 16th century. It is known that Japanese trade ships to Ming China exported Southeast Asian products such as pepper and sappanwood. They were probably obtained by the Tanegashima clan via Ryūkyū. Historians draw attention to a letter given to Ryūkyū by the
Ōuchi clan in 1542, which requested Ryūkyū to detain Tanegashima's ships. The Ōuchi clan, who rivaled the Hosokawa clan in Chinese trade, seems to have intended to bar Hosokawa from trade. Tanegashima is traditionally known as the site of the introduction of European firearms to Japan although this account is frequently questioned by historians. It is said that firearms were introduced in 1543 by the Portuguese who drifted to Tanegashima. The Tanegashima clan, led by its 15 year old
daimyō Tanegashima Tokitaka, quickly acquired the methods of producing firearms and gunpowder. Due to Tanegashima's role in the spread of firearms, firearms were colloquially known as "
Tanegashima" in Japan. == Vassalage to Shimazu ==