Like the cockney culture, the tradition of Pearly Kings and Queens can be traced to London's street traders. These traders used to elect representatives, known as "kings" in order to defend themselves against competitors and the police.
The tradition of sewing pearls onto their clothes can be traced to 1875 when a roadsweeper called Henry Croft (nothing to do with the street trader "kings") decided to raise money to help the orphanage where he was raised. In order to attract attention to himself whilst fundraising, he came up with the idea of sewing pearl buttons onto his clothes. The traders latched onto the idea and followed suit. And it is the street trader "kings" who have since become associated with elaborate suits bedecked with pearls.
An average Pearly King suit will have an amazing 35,000-odd buttons sewn on to it. Nowadays the Pearly Kings and Queens are all members of the Pearly Kings' and Queens' Association which was founded in 1911. In 1975, the original Pearly Kings and Queens Association was reformed and today it is a charitable association.
You will be very lucky to see a Pearly King or Queen just wandering around the streets. So if you want to catch a glimpse of one you should head for their annual festival held on the 1st October each year in St Martin-in-the-Fields church in Trafalgar Square.