Due to his scientific reputation, Thunberg was given the opportunity in 1776 to accompany the Dutch ambassador M. Feith to the shogun's court in Edo, today's Tokyo. During that journey, he collected many specimens of plants and animals and talked to locals along the way. It is during this time that Thunberg started writing two of his scientific works, the "Flora Japonica" (1784) and the "Fauna Japonica" (1833). The latter was completed by the German traveller Philipp Franz von Siebold, who visited Japan between 1823 and 1829 and based the "Fauna Japonica" on Thunberg's notes which he carried with him all the time in Japan.