[14][15] Following the 1720 South Sea Bubble collapse, Britain suffered an economic downturn that led to heightened social tensions.
[16] The first flurry of activity came from the Hampshire group and began in October 1721 when 16 poachers assembled in Farnham to raid the park of the Bishop of Winchester.
That proved to be the final straw, with Sir Francis Page, a "notorious hanging judge", sent to the Winchester Assizes to preside over any prosecutions; this forced the Hampshire Blacks underground.
Their main target was Caversham Park, owned by the Earl of Cadogan, with a series of increasingly-audacious raids in 1722 and 1723, including one in which a gamekeeper's son was killed.
[18] As a response to the apparent spread of purposeful and organized raids by groups of poachers, the government introduced the Black Act, formally "An Act for the more effectual punishing wicked and evil disposed Persons going armed in Disguise and doing Injuries and Violence to the Persons and Properties of His Majesty's Subjects, and for the more speedy bringing the Offenders to Justice",[13] to Parliament on 26 April 1723.
[19] At the time, it was thought that the Blacks were Jacobites, and Sir Robert Walpole encouraged the spread of that idea to advance his own interests.
[20] In March 1723, Philip Caryll was arrested by the government for drinking to the Old Pretender's health in the home of the latter's former nurse in Portsea, Portsmouth.
An innkeeper of Horndean testified that Caryll held meetings at his inn with the former Tory MP Sir Henry Goring, who fled to France after the Jacobite Atterbury Plot had been discovered in August 1722.
[21] Goring wrote to the Pretender on 6 May 1723: I had settled an affair with five gentlemen of that country who were each of them to raise a regiment of dragoons well mounted and well armed which I knew they could easily do for the men had horses and homes of their own, and were, to say the truth most of them, the persons who some time since robbed the late Bishop of Winchester's Park, and have increased in their number ever since.
[26] An offender could also be executed for setting fire to corn, hay, straw, wood, houses or barns or shooting another person.
[29] As late as the Jacobite rising of 1745–46, newspapers reported that the Blacks had reappeared in Hampshire, where they had stolen deer and robbed parks.
[32][33] Sir Geoffrey Elton claimed that the Act was "passed not in order to suppress legitimate protest but because organized gangs were destroying deer and planning a Jacobite rising".