Montesquieu

I have said above that among peo­ples who do not till the land mar­ria­ges were much less fixed, and that it was usual to take seve­ral wives. “The Germans were almost the only ones of all the bar­ba­rians who were content with just one wife,” says Tacitus,1 “if we except a few per­sons who, not out of dis­so­lu­te­ness but because of their nobi­lity, had more than one.”2

That explains how the kings of the first dynasty had so many wives. Those mar­ria­ges were less a sign of unres­trai­ned libido than an attri­bute of dignity : to make them lose such a pre­ro­ga­tive would have woun­ded them in a very sen­si­tive place.3 That explains why the exam­ple of the kings was not fol­lo­wed by the sub­jects.

[P]rope soli barbarorum singulis uxoribus contenti sunt (De moribus Germanorum [ch. xviii]).

[…] exceptis admodum paucis qui non libidine, sed ob nobilitatem, plurimis nuptiis ambiuntur (ibid.).

See Chronicle of Fredegar for the year 628.