Their importance also is to be measured not by the meagre official reports and profit and loss accounts that have survived in the West India Company's records, but by the much fuller information to be derived from Spanish and Portuguese sources, as to the remarkable daring and energy of Dutch trading agents in all that portion of the South American continent lying between the rivers Amazon and Orinoco.

Expelled from the Amazon itself in 1627 by the Portuguese from Para, the Dutch traders established themselves at different times at the mouths of almost all the rivers along what was known as the Wild Coast of Guiana, and penetrating inland through a good understanding with the natives, especially with the ubiquitous Carib tribes, carried on a barter traffic beyond the mountains into the northern watershed of the Amazon, even as far as the Rio Negro itself.

This trade with the interior finds no place in the company's official minutes, for it was strictly speaking an infringement of the charter, and therefore illegitimate.

But it was characteristically Dutch, and it was winked at, for the chief offenders were themselves among the principal shareholders of the company.
No account of Dutch commerce during the period of Frederick Henry would be complete, however, which did not refer to the relations between Holland and Sweden, and the part played by an Amsterdam merchant in enabling the Swedish armies to secure the ultimate triumph of the Protestant cause in the Thirty Years' War.

Louis de Geer sprang from an ancient noble family of Liege.