A karkashin sarki Trajan (karni na 2 AD) daular ta kai ga mafi girman fadada, tana sarrafa kusan kilomita 5,900,000 (2,300,000 sq mi) na yankin ƙasa, gami da Italiya, Gallia, Dalmatia, Aquitania, Britannia, Baetica, Hispania, Thrace, Macedonia, Girka, Moesia, Dacia, Pannonia, Masar, Asiya orarama, Cappadocia, Armenia, Caucasus, Arewacin Afirka, Levant da sassan Mesopotamia. Pax Romana, lokacin zaman lafiya, wayewa da ingantacciyar gwamnati a cikin yankunan da ke ƙarƙashin ya ƙare a ƙarni na 3, lokacin da jerin yaƙe-yaƙe na cikin gida suka lalata ƙarfin tattalin arziƙin Rome da zamantakewa Tambaya: Menene iyakar arewa?
Kogin Rhine da Danube