In the year 949, Otho, emperor of Germany, Louis IVth, king of France,
and Arnold, count of Flanders, laid siege to the town of Rouen. The duke
Richard Ist, surnamed _Sans-Peur_, made a _sortie_ by the _porte
Beauvoisine_, and fell on the enemies of which he made a great
slaughter. This action took place partly on the site of the present
_Rouge-Mare_ (red-pool), from the blood with which it was covered.
In 1450, the _Rouge-Mare_ became the horse market, which has, since the
end of the last century, been transferred to the _Boulingrin_. The
_Rouge-Mare_ is now the butter market.