Rome, the Greek World, and the East, Vol. 2 - Government, Society, and Culture in the Roman Empire

Emperors, Frontiers, and Foreign Relations 191

thefirstfourcenturiesoftheEmpireprovidesnothingremotelycomparable
withthestrategic-diplomaticmanualwhichConstantinePorphyrogenitus
wroteforhissoninabout950.^141
2.Thetypesofdecisionwhichcouldbemademusthavebeenlimitedby
thecharacteroftheinformationavailable,bothonalonger-andshort-term
basis.Itisperhapssignificantthatonesubjectonwhichourliterarysources,
atleastthoseoftheearlyEmpire,providerelativelyclearandconcreteinfor-
mationisthenumberandpositioningofthelegions(and,toamuchlesser
extent, the auxiliaries).The transferof legions from province to province
andtheraisingofnewoneswereclearlyessentialelementsinthetypesof
strategicdecisionmakingopentoemperors.^142
3.Thecharacterofthebulkoftheshort-terminformationreachingthe
emperor must have depended on the interests and objectives of persons
(mainlyindividualrulers,orwould-berulers)beyondtheEmpire,oronthe
presumptionsofgovernorsormilitarycommandersonthefrontiers.
4.HowtheEmpirecouldrespondtoanyperceivednecessityonthefron-
tiers will have been determined first by the degree of initiative allowed
tocommandersinthearea,andtheextenttowhichtheyoperatedwithin
theexplicittermsorunspokengeneralassumptionsofanyimperial‘‘grand
strategy.’’
5.Insofarasdecisionswereheldtoberequiredatthecentre,thatis,bythe
emperor,itisessentialtorememberthecrudefactthattheemperorcould
beawareofnothingbeyondthereachofhisowneyesexceptwhatsomeone
wishedorfeltobligedtotellhim.Withallcommunicationsmadetohimwe
havetorecallconstantlythecontrollingfactorsofspaceandtime,thatis,the
delaysofuptosometwomonthsbeforeamessengercouldreachhim,and
uptoafurthertwomonthsforthereturnjourneytotheareaconcerned;and

cussions,editedbyM.W.C.HassallandR.I.Ireland,BARInt.Ser.63,1979)isofcourse
moreoriginal,beingconcernedwithpracticalmeasuresforthedefenceofastaticfrontier.

141. ConstantinusPorphyrogenitus,deAdministrando,ed.,trans.,andcom.G.Moravcsik
     andR.J.H.Jenkins,I–II(1949–62).Foritsimportanceasasourceofethnographicalinfor-
     mationontheareanorthoftheBlackSea,seeD.Obolensky,The Byzantine Commonwealth:
     Eastern Europe, 500–1453(1971),esp.24–25.


142. SeeJosephus,BJII,16,4(345–401),thespeechofAgrippaII;Suetonius,Vesp.8;
     Tacitus,Ann.4,5;Hist.1,8–11;2,81.Noteesp.Dio55,23–24,onthepositioningofthose
     legions which had existed under Augustus and were still in service, and those raised by
     successivelateremperors.ItwillberecalledthataccordingtoSuetonius,Tib.30,Tiberius
     usedtoconsulttheSenate‘‘delegendovelexauctorandomiliteaclegionumetauxiliorum
     discriptione’’(seetranslationintextton.16).