Blackguard (pronounced blaggard) is a rather old-fashioned term for a scoundrel.
“In all great houses, but particularly in the royal residences, there were a number of mean and dirty dependants, whose office it was to attend the sculleries etc. Of these (for in the lowest deep there was a lower still) the most forlorn wretches seem to have been selected to carry coals to the kitchens. To this smutty regiment… the people, in derision, gave the name of black-guards” (Ben Johnson, ‘Love Restored’, 1612)
The lowest-of-the-low in a traditional Royal household, the black-guard was responsible for carrying coals and other kitchen utensils between palaces. The term was later used as an insult. As social and economic inequality is currently reaching extraordinary heights, Jenna Finch and Simon Raven perform by re-visiting this image, ineffectually guarding lowly objects at the festival entrance.