Laws about only allowing the oldest son to marry were certainly believed
to be in existence in some areas and in certain jurisdictions, whether
that was the case or not.
It's the only explanation I can think of for the fact that my 4xgreat
grandfather and his older brother lied about their relative ages on the
former's civil marriage record in 1832 in Bonn, Regierungsbezirk Coeln.
which had become part of Prussia in 1815, after years of checkered
history and French rule.
Anselm Ungar brought a one-year-old child into the marriage, while his
older brother Leopold, a witness on the record, was still unmarried.
The discrepancy caused all sorts of difficulties
on the family's later civil records, and I've not yet disentangled all
the facts about the whole episode.
St Albans, UK
St Albans, UK.