Complex sentence: Because people in North Brabant wore usual dark clothing on daily bases, even during their wedding (black) and other social occasions, the women showed that they were mourning by wearing a special poffer over a long period of time.
Split into simpler sentences: Because people in North Brabant wore usual dark clothing on daily bases, even during their wedding (black) and other social occasions. Therefore the women showed that they were mourning by wearing a special mourning poffer over a long period of time.