Mr. Portman to Mr. Seward

No. 36.]

Sir: I have the honor to transmit herewith, No. 1, copy of a memorandum, signed on the 21st instant by the representatives of the four powers, who, in September last, adopted the policy of reopening the Inland Sea, closed against foreign vessels by the aggressions of the Prince of Choshu, at Simonoseki, which policy was crowned with success, and met with the approval of their respective governments.

The present memorandum is in continuation of that policy, in view of the approaching operations of the Tycoon at the head of his army for the suppression of the rebellion of the Prince of Choshu, and with the object of securing the observance of strict neutrality.

I trust you will be pleased to approve of my action.

I have the honor to be, sir, very respectfully, your most obedient servant,

A. L. C. PORTMAN, Chargé d’ Affaires ad interim in Japan.

Hon. William H. Seward, Secretary of State, Washington.

No. 1.


Choshu, Prince of Nagato, being in a state of overt insurrection against the Tycoon, and his Majesty the Tycoon having resolved to march himself at the head of an army, intended to reduce his contumacious vassal to obedience, civil war is imminent, and from the situation of its theatre may, to a certain extent, compromise the interests of the treaty powers by impeding the free navigation of their vessels through the straits of Simonoseki.

In presence of this state of things, the representatives of the four powers subscribing the convention of the 2’2d October, 1864, have met for the purpose of consulting as to the measures it may be convenient to adopt for protecting the interests of their countrymen, and securing the results contemplated by the expedition successfully directed by their respective naval forces against the batteries of Simonoseki in September, 1864.

This meeting took place on the 21st June, 1865, and the following is the result of the joint deliberations of the undersigned:

Considering that the batteries erected by the Prince of Nagato, in the straits of Simonoseki, were employed to prohibit the free navigation of the inland sea to foreigners, and were disarmed by the commanders of the allied forces, who imposed upon the prince the formal obligation not to re-arm them:

Considering that the allied forces have not renounced the obligation of a military position in the straits, save on a formal obligation accepted by the government of the Tycoon, to guarantee the free navigation of the straits to foreign vessels:

Considering, moreover, that while the rules of a wise policy require of the powers signing the convention to avoid every act of intervention in the conflict which has just commenced between the Tycoon and the Prince of Nagato, their treaty relations of friendship and commerce which exist only with the Tycoon require from them the moral support and facilities necessary to the exercise of the rights acknowledged by such treaties to belong to the Tycoon:

For these reasons the undersigned have adopted with one accord the following articles, and are agreed that a copy of this memorandum shall be addressed to the commanders of the naval forces of their respective nations now present or hereafter to arrive in Japan:

Article I.

In the interval which will elapse before the land and sea forces of the Tycoon shall present themselves in the straits of Simonoseki, the naval commanders of the powers, parties to the convention of the 22d October, ought, in virtue of that convention, to oppose the re-armament of the batteries of the Prince of Nagato in the said strait, or even to proceed to their disarmament if the Daimio should have re-armed them; but as the carrying these measures into effect might bring about conflicts and complications, which the undersigned wish absolutely to avoid, the commanders of the naval forces are requested, in this latter case, to make to the Prince of Nagato, or his representative, such remonstrances as they may deem appropriate, and in any event to ascertain the state of things, and to furnish the undersigned with an immediate report, in order that they may communicate with the government of the Tycoon thereon, and to place their respective governments in a position to give their instructions.

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Article II.

Apart from the object of the preceding article, it is desirable that the commanders of the naval forces should be able to assure the free passage of the straits to foreign ships using it in regular trade with Japan, and to lend the aid required by treaty for repressing on the part of the merchant ships belonging to their respective flags in any part of the territories of Nagato, contiguous to the straits, trading operations, which, in terms of the treaties, are only authorized in the ports actually opened to foreigners.

Article III.

It is equally important to prevent the ships of the Tycoon, charged with the prevention of unlawful commercial operations with the insurgent prince, from going in such cases beyond the limits of right and humanity.

Article IV.

When hostilities shall commence in the straits between the Tycoon and Choshu, the commanders will warn foreign ships of the necessity of passing beyond the lines of fire, and should even require them to abstain from entering the straits if the passage at the time should bring them into actual danger.

Article V.

It is well understood that all the measures indicated by the undersigned shall be carried out in the manner which the naval commanders shall consider most fitting, and in any case that their desire is that the strictest neutrality should be observed in all that concerns the military operations between the Tycoon and the Prince of Nagato.

A. L. C. PORTMAN, Chargé d’Affaires ad interim of the United States in Japan.

LEON ROCHES, Minister Plenipotentiary of France in Japan.

CHARLES A. WINCHESTER, H. B. M’s. Chargé d’ Affaires in Japan.

D. DE GRAEFF VAN POLSBROEK. H. N. M’s Political Agent and Consul General in Japan.