The sovereign may, in his private capacity, hold property and become party to a suit like any citizen.[180] A sovereign may travel incognito, and is then entitled only to the recognition accorded to the rank which he assumes. He can, however, assert his sovereign capacity and obtain its immunities at any time should he deem it proper.
[§ 63. Exemptions of State Officers]
(a) Diplomatic agents, or those commissioned to transact the political affairs of the state abroad, are conceded a wide immunity from local jurisdiction. As representing the political will of their state, diplomatic agents have immunities similar to those conceded to the sovereign, though by virtue of the fact that the sending of diplomatic agents has long been a common practice, their immunities are quite well defined. These immunities will be considered more in detail under the subject of International Intercourse, but in general a diplomatic agent is exempt from, (1) criminal jurisdiction, (2) civil jurisdiction, (3) local police and administrative regulations, (4) taxes and duties, (5) jury and witness duty, (6) regulations in regard to religious and social action, (7) all exercise of authority by the local state within his official residence or hôtel, (8) and from the exercise of similar authority over his household, official and unofficial.
(b) The exemptions granted to consuls vary in different states and under different circumstances. In general they are entitled to such exemptions as will enable them to perform their functions effectively.[181]
(c) Any foreign army within the territorial limits of a given state, by permission of the sovereign of said state, is free from the sovereign's jurisdiction. Chief Justice Marshall, in 1812, gave as his opinion: "In such case, without any express declaration waiving jurisdiction over the army to which this right of passage has been granted, the sovereign who should attempt to exercise it would certainly be considered as violating his faith.... The grant of a free passage, therefore, implies a waiver of all jurisdiction over the troops during their passage, and permits the foreign general to use that discipline, and to inflict those punishments, which the government of his army may require."[182] Permission, either general or special, must be obtained in order that an army may enter a foreign state in time of peace. The army must cause the least possible inconvenience to the state during its sojourn.
The military attaché of an embassy is regarded as a member of the official household of the diplomatic agent.
(d) Navy. As a vessel of war can without inconvenience to a foreign state pass through or remain within its maritime jurisdiction, it is customary to accord to the vessel and crew immunity from local jurisdiction and freedom of passage unless withheld for special reason. "Their immunity from local jurisdiction has come to be more absolute than that of the official residence of ambassadors, and probably for the reason that they have the efficient means of resistance which an ambassador has not."[183]
In general the exemption from local jurisdiction which a vessel of war enjoys in a foreign state extends: (1) to acts beginning and ending on board the vessel;[184] (2) to all boats, etc., of the vessel of war in charge of the crew of the vessel and upon its service; (3) to freedom from customs and all such regulations as are not necessary for the safety of the port (it was held in case of the United States frigate Constitution, in 1879, that she was not liable to salvage charges;[185] the vessel is therefore liable to quarantine, anchorage, etc., rules which imply no derogation of sovereignty); (4) to all persons on board the vessel whether members of the crew or others. This exemption should not be taken as warranting a general exercise of the right of asylum on board vessels of war. Asylum can be granted as an act of hospitality to a political refugee, who cannot use the vessel as a base for political intrigue. Asylum to common criminals cannot be granted without offense to the foreign state. Such criminals are usually surrendered on request of the local authorities.
A commander cannot pursue deserters on shore or exercise external authority.
Hall sums up the general principle as follows, "The immunities of a vessel of war belong to her as a complete instrument, made up of vessel and crew, and intended to be used by the state for specific purposes; the elements of which she is composed are not capable of separate use for those purposes; they consequently are not exempted from the local jurisdiction."[186]