were inviolable, so that no executions against property could be carried out there.  Otherwise, diplomats were obligated to obey the law of the country to which they were posted.  As an offender against the law of nations, Hotman maintained, Mendoza should be imprisoned and not merely expelled.

In the event, expulsion was the punishment meted out. Menodoza reacted with typical aggressiveness.  He refused to depart from the country until he had informed his king (Philip II of Spain) of what had happened. He duly informed Philip, with some degree of understatement, that “public indignation is very great against me.”  Indeed, pamphleteers generally called for harsher treatment.  When told that he was fortunate not be punished more severely, Mendoza reportedly scoffed at the idea.  He was forcibly placed onto a boat bound for France – while warning his disgruntled hosts that his master would avenge this insult with war.  (War did indeed break out between England and Spain in the coming years, but this was largely over English support for Dutch rebels rather than for the summary dispatching of Mendoza.)

The principal actors in this little drama all went on to various degrees of distinction.  Following a brief sojourn in Wittenberg in Germany, Gentili returned to Oxford in 1587, now as Regius Professor of Civil Law.  (The chair is currently held by Boudewijn Sirks.)  Both he and Hotman took good advantage of their labors to publish treatises on diplomatic law.  Gentili set out his ideas in De Legationibus in 1585, the year after the Mendoza affair.  It was his first major contribution to international-law scholarship.  Hotman wrote a treatise entitled L’Ambassadeur in 1603 – although his renown was compromised by accusations that he had plagiarized a previous work by an Italian writer named Carlo Pasquali.

As for Mendoza, there were further adventures in store.  He showed little penitence for his past conduct. His next posting was to France, where he once again became active (to put it mildly) in local politics.  Specifically, he became deeply embroiled in the machinations of the Guise faction, who were extreme Catholics, in the religious civil strife that was then tearing France apart.  His chief role was to act as paymaster for the funnelling of Habsburg funds to the Guise forces.  He also helped organize the Day of the Barricades in 1588, in which a revolt by Catholic extremists drove King Henry III from Paris. There is also evidence of support, from afar, for another assassination plot against Elizabeth I (the Babington plot of 1586).  For these various initiatives, Henry III demanded of Philip II that he recall his all-too-energetic representative. Philip declined to do so, and Mendoza only left France in 1591, when blindness was overtaking him.

Perhaps his disability mellowed him, as he turned his attention in his last years to scholarly pursuits. His most notable contribution was a treatise on warfare, written in 1596 and translated (from Castilian) into Latin, English, and German.  He also wrote a commentary on the Dutch wars, which was strikingly fair-minded, given his high-level involvement on one side.  Finally, he translated a portion of the writings of the Dutch (Protestant) scholar Justus Lipsius.  It appears that he even dabbled in poetry.  He also, somewhat ironically, made a contribution to English historical studies, in that his dispatches to Spain became a useful source of information about the English political and diplomatic scene at the time.  He died in Spain in 1604 – fittingly, the year in which England and Spain brought the war between them to a conclusion in the Treaty of London.

For those who seek further detail on this incident, useful information may be found in an excellent book by Linda S. Frey and Marsha L. Frey, The History of Diplomatic Immunity (1999). The current law on the subject is set out in the Vienna Convention on Diplomatic Relations (of 1961), which is rather more indulgent towards wayward ambassadors than the English government was in 1584.  According to the Convention, a person in Mendoza’s position has full immunity from criminal prosecution in the receiving state (unless it is waived by the sending government).  All that the host government can do is to declare the offending envoy persona non grata and require his departure.  It should be noted that this is not, strictly speaking, what was done in the Mendoza affair.  Mendoza’s expulsion was regarded as punishment for an offense committed under international law – punishment inflicted by English authorities, who did not hesitate to assume jurisdiction over their troublesome envoy.  Neither Gentili nor Hotman held that Mendoza possessed a blanket immunity against prosecution.  It may be left to the rumination of readers whether the Vienna Convention approach really represents an improvement over the law as it stood in the 16th Century.