144 The Imperial Government
ametallum principisorthesacra moneta(imperialmint).^40 Therewerecertainly
both private and imperial mines; it is equallycertain that free labour, and
normalslavelabour,couldbeemployedinboth.WhenTertullianelsewhere
(De Cult. Fem.1,5,1)characterisesgoldandsilverastheproductofconvict
labour(poenale opus),heisonceagaingeneralisingforrhetoricalpurposes.
Itcouldnotevenbestrictlyprovedthatallthosecondemnedad metallum
workedinimperialmetalla.Itisnatural,andperhapscorrect,toassumethat
theydid;andthiswouldexplainwhyithadtobecarefullyreiteratedbythe
lawyersthatsuchpersonsbecamenot‘‘slavesofCaesar’’or‘‘slavesofthefiscus’’
but‘‘slavesofthepenalty[poena]’’;butinfactthesameprinciplewasheldto
applytothosecondemnedtothesword,oradbestias.^41 Furthermoretheother
evidencefortheuseofimperialpropertiesasplacesofdetentionorexileall
relatestoindividualupper-classvictims,^42 andaffordslittlebasisfortheidea
thatsuchpropertiesmighthavebeenusedonanextensivescaleforthispur-
pose.TheonlysignificanthintofsuchageneralusecomesinValerian’sorder
of258thatCaesariani(imperialslaves)whopersistedinChristianityshould
beboundandsentofftoCaesarianae possessiones(Cyprian,Ep.81,1,2).There
is,however,nopositiveindicationthattheyweretobeputtoworkthere.
Mostimperialpossessions,likemostpropertyintheancientworld,willhave
consistedofland.Itisperhapsthemostsignificantfeatureoftheuseofcon-
victlabourundertheEmpirethatitseemsnevertohavebeenemployedon
themostimportantworkofall,thatontheland(seebelow).
However, in spite of these reservations, there are clearcases of convict
labourbeingemployedinimperialminesandquarriesunderthecontrolof
imperial officials, and conversely no definite evidence for its being made
available for private exploitation. It is therefore reasonable to assume that
theconvictsdidworksolelyinmetalla Caesariana.Ifthatisso,thenthepossi-
bilityofsuchaformofforcedlabourwasafunctionofthegradualspreadof
imperialownershipofpropertiesofalltypes.Theopportunitythusexisted
to combine the notion of applying physically degrading penalties to free
personswiththeexistenceofpropertiesofvariouseconomictypes.There
might (in principle) therefore have been a significant general deployment
ofconvictlabourbywayofdirectexploitationoftheseproperties.Butin
factourinadequateevidencesuggeststhatimperiallandedpropertieswere
moreoftenleasedoutforacashrentthanexploiteddirectlythroughaslave
40.Dig.48,13,8,1;19,38pr.Pauli Sent.V,21a,1.- See,e.g.,Dig.28,3,6,6;29,2,25,2–3;34,8,3pr.;48,19,12;17pr.
42.ERW,182.