Citadel of the Saxons. The Rise of Early London. By Rory Naismith. London: I.B. Tauris. 2019. 288 pages. 28 figures; 5 maps. £20. ISBN 9781788312226.The Imperial City of Cologne. From Roman Colony to Medieval Metropolis (19 b.c.-1125 a.d.). By Joseph Huffmann. The Early Medieval North Atlantic. Amsterdam: Amsterdam University Press. 2018. 280 pages. 1 figure. €105. ISBN 9789462988224.