The Baker Street irregulars are a gang of street Arabs whom Holmes employs from time to time to aid in his investigations. This back-street brigade serves to gather information, find missing people, track individuals, deliver communications, etc.
This urban army appears in the first Sherlock Holmes story, A Study In Scarlet. They also have their own chapter in a subsequent novel, The Sign of the Four. They reappear some years later in The Adventure of the Crooked Man.
Wiggins, whom Holmes paid a shilling per day (plus expenses), with a guinea prize (worth one pound and one shilling) for a vital clue. Of course, the irregulars are often included in various movies, television programs, and Sherlock Holmes pastiches. Indeed, they play a prominent role in several of the stories in my collection – Sherlock Holmes – The Golden Years. However, as my stories take place nearly twenty years after their last appearance, the the irregulars in my stories are led by a sixteen-year old boy named Archie, who has a tag-along little brother names Benjie.