Keeping Kings in Check 89Th e reprisal pro cess was subject to close judicial scrutiny. In requesting
the letter of reprisal, the allegedly injured party had to provide evidence to
his government of the wrong and of the amount of damage actually suf-
fered. Th e letter would state on its face the quantity of damage adjudged to
have been sustained— and that amount would then be the upper limit that
the merchant could take from the fellow nationals of the wrongdoer. Any
property which he captured had to be brought before a court for valuation
to ensure that he was not being excessively generous (to himself) in his in-
demnifi cation enterprise. Once the offi cial valuation fi gure was attained,
confi scations must halt.
With some modest adjustments, this letter- of- reprisal system could oper-
ate on the high seas as well. In this case, the holder of the letter would be
authorized to fi t out a ship and to carry out his property captures on the high
seas. Th is authorization was commonly referred to as a “letter of marque,” on
the basis that it permitted the holder to go outside the territory of his state
(i.e., beyond the frontier, or mark in German) to obtain his compensation.
It will immediately be appreciated how close this practice came to being
mere piracy, which was robbery committed on the high seas. What distin-
guished lawful reprisals from piracy was the possession by the captor of a
letter of marque from his sovereign.
Th is practice of reprisals, as just described, was a purely medieval invention,
having no roots in Roman law. In Roman law, responsibility was entirely per-
sonal, with no element of collective responsibility or, as it were, guilt by associa-
tion. For that reason, lawyers tended to look askance at the practice. One such
was the Italian Alberic of Rosate, a prominent practicing lawyer in Bergamo
(and the author of a noted treatise on municipal statutes in the Italian cities).
Writing in the early fourteenth century, he asserted that the practice of repri-
sals was contrary to natural law— but that it was allowable nonetheless when
there was no mutual superior over the two states involved. Th at reprisals be-
came fully accepted in practice is evident from no less an authority than Barto-
lus, who wrote a treatise on the subject. Th e substance of this found its way, in
turn, into John of Legnano’s book, alongside his exposition of the law of war.
Bonet and Christine de Pisan also treated the subject in their works.
A disturbing feature of reprisals was that they could be all too easily abused.
An unscrupulous merchant might obtain a letter of reprisal on the basis of a
false claim. Or the quantity of the loss suff ered might be exaggerated. Th ere