George Anton Schaeffer:

This is the second book of a biographical trilogy about German physician George Anton Schaeffer (1779-1836), who administered (in the first book) a secret plan of Russian Tsar Alexander I to kill Napoleon Bonaparte from a balloon during the French invasion of Russia in 1812, then (in this book) as ship's surgeon on the Russian navy ship SUVOROV's 'reverse circumnavigation' to the Russian-American Company's outpost in Sitka, Alaska, he is stranded as a guest of Russian-American Governor Alexander Baranov, who sends him to the Hawaiian islands where he meddles in island politics during the reign of King Kamehameha, ruling the island of Kauai as co-regent with its last independent King Kaumuali'i in 1816-7, and finally winds up (in the third book of the trilogy) founding a plantation colony in Brazil called Frankenthal and transporting to Brazil thousands of German mercenaries and their families on behalf of Brazil's first independent Emperor Dom Pedro I and his Hapsburg wife, Dona Leopoldina.