I had always imagined the former, but I realize the viking Longships and battle of Svolder were contemporary with Galleys in the Mediterranean who fought using rowers.
Were there any differences between Northern naval tactics and those of the Mediterranean during 1,000 CE?
I have been told East Rome mounted catapults on their larger ships during this time. Where these effective in naval combat, and where they common?
I suppose the Vikings made use both of sail and oars as long as they could, and the latter (oars) were also sometimes to show the size of the warship as tvítugsessa ('Twenty-bencher [for oar rowers]') in medieval Scandinavian law books and Icelandic sagas.
'315. The men from Vík should provide sixty twenty-benchers, and in addition a ship from Grenland (Lower Telemark). The men from Egðafylki should provide sixteen twenty-five-benchers. The men from Rygjafylki should provide twenty-four twenty-five benchers. And the men from Hörðafylki the same. The men from Sygnafylki sixteen twenty-five-benchers. The men from Firðafylki twenty twenty-five benchers. The men from Sunnmøre sixteen twenty-five benchers. The men from Romsdalen ten twenty-benchers. The men from Nordmøre twenty twenty-benchers. The men from Trøndelag eighty twenty-benchers. The men from Namdalen nine twenty-benchers. The men from Hålogaland hirteen twenty-benchers and one thirty-bencher, seven in the southern part and six in the northern part, because they have to keep the watch eastward (Older Gulathing Law, Chap. 315, the translation is taken from: Simensen trans. 2021: 210).
The lawbook also specifies the number of minimum vacant seats in the benches if conscripted farmers does not appear in time so that the ship cannot be mobilized as the king intended, so I suppose the oars were also at least nearly the same as important as the sail (Chaps. 305 and 308 in the Older Gulathing Law in fact have relevant regulations) for the warship:
'300.......They are not ready for sailing when five oar benches or ore are vacant on a twenty-bencher...... (Simensen trans. 2021: 202).
On the other hand, I cited and compare the main extant texts on the battle of Svolder before in: Use of the Iron Ram in the battle of Svolder, how did it work?. From these accounts, I'm rather not so positive to find much information on the Viking Age naval battle in later sagas.
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