After an initial convention between the United States and Japan in 1854 (Convention of Kanagawa), the United States, the Netherlands, Russia, Great Britain and France succeeded each in concluding a treaty of amity and commerce with Japan in 1858, the so-called Ansei Treaties.
In its appendix, the Japanese Government stated that it had no objections against a similar treaty with the Kingdom of Portugal, if such was desired by that country.
During the negotiations, Guimarães aimed for a reduction of the Japanese import tariff of 35% on wine, but this concession was refused by the Shogunate.
[1] The Treaty of Amity and Commerce between Portugal and Japan was officially signed on 3 August 1860 in Edo by Isidoro Francisco Guimarães for Portugal, and Mizuguchi Sanuki no kami (溝口讃岐守), Sakai Oki no kami (酒井隠岐守) and Matsudaira Jirobe (松平次郎兵衛) for the Shogunate.
[5][6] The most important articles of the Portuguese-Japanese Treaty of 1860 are as follows:[6] The first Portuguese Consul in Japan was José Loureiro, Representative of the Company Dent & Co. in Yokohama, who took up the consular position in 1860.