Blackthorne’s letters of marque

Blackthorne’s letters of marque are the legal instruments that distinguish his expedition’s authorized warfare from piracy in Blackthorne’s account, and that he later invokes when proposing to seize Portuguese wealth at sea. Their power is neither universal nor uncontested: they authorize action against enemies beyond Japan, but do not give foreigners permission to disregard the laws Toranaga enforces on Japanese soil.

Definition and Scope

A letter of marque is a license issued by a crown or government granting authority to wage war against an enemy. Blackthorne explains that the Dutch authorities authorized his ships to carry the war into seas and places dominated by their opponents and to find markets for their goods. The document therefore combines a military commission with a commercial purpose: it permits attacks on enemy interests while also supporting the expedition’s search for trade.

That authorization is central to Blackthorne’s answer when Toranaga asks whether he is a pirate. Blackthorne defines a pirate as an outlaw who rapes, kills, or plunders for personal profit, then contrasts that status with his own government’s permission to attack. He acknowledges that the Spanish and most Portuguese regard the Dutch as pirates and religious heretics, but insists that his fleet’s actions have legal sanction from its own rulers. The exchange makes clear that the label depends on which political authority is doing the judging: the same violence can be framed as licensed war by one side and criminal predation by another.

The Permit and the Expedition

Blackthorne’s expedition came to Japan primarily to trade, though its members carried letters of marque authorizing attacks on their enemies in the New World. He tells Toranaga that the fleet did not arrive intending to wage war in Japan; it came to trade in a region the Portuguese and Spanish had kept closemouthed about. His stated position is conditional: he would fight the Portuguese or Spanish if they fought him, rather than claim that the license itself required hostilities in Japan.

The papers were missing when Blackthorne described his voyage to Toranaga. He said that his maps, rutters, letters of marque, and other documents had been removed from his ship. Their loss mattered practically as well as politically: the papers could have helped him explain his route through the Pass of Magellan, while the license would have documented the expedition’s claimed authority. Blackthorne could describe what it permitted, but the physical document was not available to show Toranaga at that point.

Maritime Knowledge and Political Leverage

The letters belong to a larger system in which control of information and routes determines what a ship can safely attempt. Navigational charts are vague, longitude cannot be fixed, and a pilot depends on accumulated observations recorded in a rutter: courses between ports and capes, depths, currents, winds, hazards, and places to provision or repair. Such books are valuable precisely because knowledge of routes can turn an unknown sea into a traversable one. Portugal and Spain guard their overseas rutters as national treasures, while their Dutch and English enemies seek them. A license to attack, however, does not itself supply the navigational knowledge needed to reach a target or return safely.

Blackthorne later turns the letters into a bargaining proposal. He suggests that Toranaga authorize him to take the Portuguese Black Ship, offering to split its cargo of silks and bullion and arguing that the ship could be captured beyond the three-mile limit, in international waters. He presents the seizure as a prize permitted by his existing commission, with the possibility of bringing the vessel and its cargo to Yedo and paying Toranaga half the value as a port tax. The proposal makes the letters more than a defense against the charge of piracy: they become a possible instrument for redirecting Portuguese wealth and trade.

Limits in Japan

Toranaga does not treat foreign commissions as a license to act inside Japan. He tells Blackthorne that what foreigners do at sea or in their own countries is their affair, but that in Japan foreigners are present by permission and public mischief or quarrels are punishable by death. His distinction is jurisdictional: a European government may authorize Blackthorne’s actions against its enemies, but Toranaga’s laws govern conduct on Japanese land.

That limit shapes Blackthorne’s argument about Nagasaki and Lord Harima. He says that Nagasaki is in fact controlled by foreigners, especially the Portuguese, and invokes his legal right to attack an enemy anywhere. Toranaga’s response, conveyed through Mariko, is that this is not simply another place in which the commission can be exercised: Japan is the Land of the Gods, and an attack there is unthinkable. Blackthorne agrees with the principle as stated, while adding that the same plan might become relevant if Lord Harima or the Jesuits who lead the Portuguese turned hostile. The exchange leaves the authorization conditional and politically dangerous, not a settled permission to attack.

The letters thus expose a clash between legal systems rather than resolving it. To Blackthorne, his commission makes warfare against Portuguese interests lawful under the authority that issued it; to Toranaga, foreign authorization cannot displace Japanese sovereignty or local law. Their significance lies in that gap between permission and jurisdiction: at sea, the letters can support a claim to capture enemy shipping, but in Japan their force depends on Toranaga’s consent.