It is a long held tradition across Europe that chimney sweeps bring good luck. Most famously, some 200 years ago King George II was riding his horse in a royal procession when without warning a stray dog began nipping the legs of the king’s horse causing it to rear up and the king to lose control. As the crowd looked on in horror, a chimney sweep came from the crowd, regained control of the horse and returned to the crowd as quickly as he had arrived. After the procession the king was unable to thank the sweep personally for his bravery, so he decreed that from that day forward all chimney sweeps are bearers of good luck and should be treated with respect. To this day chimney sweeps are still invited to attend special events to ensure good luck.
As far as the tradition of sweeps bestowing a marriage with luck is concerned, it is on record that before the Duke of Edinburgh married the Queen in 1947 he slipped out of his apartment to shake hands with a sweep who just happened to be passing by!