Changes

Following unification, Ryûkyû generally sent tribute once every two years, though the pattern changed at times along with shifts in Chinese politics. The Ming Court placed restrictions on the size and frequency of Ryukyuan missions in [[1472]], lifting these restrictions in [[1507]] after repeated Ryukyuan petitions, restoring the pattern to annual tribute missions.<ref name=tanaka>Tanaka Takeo, "Japan's Relations with Overseas Countries," in John Whitney Hall and Toyoda Takeshi (eds.) ''Japan in the Muromachi Age'', Cornell University East Asia Program (2001), 159-178.</ref> Special missions were sent following the [[Chinese investiture envoys|investiture]] of a new king of Ryûkyû, to express gratitude for imperial grace (C: 謝恩, ''xiè'ēn''), and following the accession of a new emperor to the Chinese throne, to offer congratulations (C: 慶賀, ''qìnghè'').<ref name=schott176>Schottenhammer, "Empire and Periphery?", 176.</ref>

Following unification, Ryûkyû generally sent tribute once every two years, though the pattern changed at times along with shifts in Chinese politics. The Ming Court placed restrictions on the size and frequency of Ryukyuan missions in [[1472]], lifting these restrictions in [[1507]] after repeated Ryukyuan petitions, restoring the pattern to annual tribute missions.<ref name=tanaka>Tanaka Takeo, "Japan's Relations with Overseas Countries," in John Whitney Hall and Toyoda Takeshi (eds.) ''Japan in the Muromachi Age'', Cornell University East Asia Program (2001), 159-178.</ref> Special missions were sent following the [[Chinese investiture envoys|investiture]] of a new king of Ryûkyû, to express gratitude for imperial grace (C: 謝恩, ''xiè'ēn''), and following the accession of a new emperor to the Chinese throne, to offer congratulations (C: 慶賀, ''qìnghè'').<ref name=schott176>Schottenhammer, "Empire and Periphery?", 176.</ref>

Tribute was sent in a variety of forms, including [[Ryukyuan horses]], [[sulphur]], [[salt]], [[lacquerwares]], sword-polishing stones, and cowhides, and Southeast Asian goods including aromatic woods, pepper, rhino horn, and other animal products. Ryukyuan ships sent to China, like Chinese investiture envoys' ships to Ryûkyû, were known as ''okansen'' ([[Okinawan language|O]]: ''ukwanshin'')<!--冠船-->; trading ships accompanying the embassy vessels were known as ''sekkôsen''<!--接貢船-->.<ref>This term was also used for Ryukyuan officials traveling to Fuzhou to meet investiture envoys, to then travel with them back to Ryûkyû. As the Court granted Ryûkyû tax exemptions for trade performed by these ''sekkôsen'' (C: ''jiē gòng chuán''), they were used as trading vessels at that time as well. Schottenhammer, "Empire and Periphery?," 176, 181.</ref> While hosting Chinese envoys was quite expensive for the kingdom, the interaction was beneficial for the kingdom, which generally received more in gifts from China than it gave in tribute.<ref>Gregory Smits, "Ryukyu and its Geo-cultural Context," presentation at Parades & Processions Joint Event, University of Hawaii at Manoa, 10 Feb 2013.</ref>

Tribute was sent in a variety of forms, including [[Ryukyuan horses]], [[sulphur]], [[salt]], [[lacquerware]]s, sword-polishing stones, and cowhides, and Southeast Asian goods including aromatic woods, pepper, rhino horn, and other animal products. Ryukyuan ships sent to China, like Chinese investiture envoys' ships to Ryûkyû, were known as ''okansen'' ([[Okinawan language|O]]: ''ukwanshin'')<!--冠船-->; trading ships accompanying the embassy vessels were known as ''sekkôsen''<!--接貢船-->.<ref>This term was also used for Ryukyuan officials traveling to Fuzhou to meet investiture envoys, to then travel with them back to Ryûkyû. As the Court granted Ryûkyû tax exemptions for trade performed by these ''sekkôsen'' (C: ''jiē gòng chuán''), they were used as trading vessels at that time as well. Schottenhammer, "Empire and Periphery?," 176, 181.</ref> While hosting Chinese envoys was quite expensive for the kingdom, the interaction was beneficial for the kingdom, which generally received more in gifts from China than it gave in tribute.<ref>Gregory Smits, "Ryukyu and its Geo-cultural Context," presentation at Parades & Processions Joint Event, University of Hawaii at Manoa, 10 Feb 2013.</ref>

For a time, the Ryûkyû Kingdom also sent tribute to the [[Ashikaga Bakufu|Ashikaga shogunate]] once every three or four years. Tribute and trade goods carried by these ships included [[currency|Chinese copper coins]], wine, <i>nanban</i> silks, aloe, sappanwood, and other scented and medicinal products, many of them obtained from Southeast Asian ports or from Iberian traders.<ref name=tanaka/>

For a time, the Ryûkyû Kingdom also sent tribute to the [[Ashikaga Bakufu|Ashikaga shogunate]] once every three or four years. Tribute and trade goods carried by these ships included [[currency|Chinese copper coins]], wine, <i>nanban</i> silks, aloe, sappanwood, and other scented and medicinal products, many of them obtained from Southeast Asian ports or from Iberian traders.<ref name=tanaka/>