The Comstock family is one of a fairly old and respected name, originating in modern-day Britain. The Comstocks are descendants of the Welsh knight Gruffud Cymstock, a native of Gwent and adviser to Rhys ap Tewdwr, the King of Deheubarth. The historical family home of the Comstocks is Gruffud Castle in Monmouthshire, which until recently was vacated save for a contingent of house-elves who kept the place in shape. In addition, the two Canadian mansions used as family estates have been sold off and a third estate located in St. Catherine's, Ontario, now bears the title of Comstock Family Estate. Since the Acts of Union, the Comstock family have largely stayed out of mainstream politics and have instead served their wizarding communities as enforcers of law and justice.
Although originating in Wales, members of the Welsh branch of the Comstock family are few and are rather unknown in wizarding Britain; the family did not make the Sacred Twenty-Eight because Cantankerus Nott didn't think any Comstocks remained in Britain. The Comstocks' fall from prominence in wizarding Britain is solely due to the fact that most of the family had migrated to the New World by the end of the 17th century. The only member of the paternal line that remained was the original Lloyd Maldwyn Comstock, who returned to Britain following the Salem Witch Trials. The Welsh Comstocks, known by their Canadian cousins as the "Old Breed," have a tradition of home-schooling their children and have been among the most ardent critics of Hogwarts' educational system in the past. Only three Comstocks have ever attended Hogwarts: Urian Wynne Comstock, who attended from 1812 to 1819, found the House politics and popularity hierarchy disgusting and refused to ever let his children attend; Lloyd Maldwyn Comstock IV, who attended between 1943 and 1945, was pulled out by his parents after the death of Myrtle Warren; and Lloyd Maldwyn Comstock V, who attended between 2008 and 2015. All of them were Sorted into Slytherin.
The Canadian branch of the Comstocks began with the widespread migration of family members to the British colonies of the New World. Grigor Hywel Comstock, the family's patriarch, built an estate in Virginia and housed most of his family there. After the Salem Witch Trials, most of the Comstocks remained and became "founding fathers" of the General Congress of American Wizards, with Arthur Maxen Comstock writing the original constitution and set of laws for the new government, which was dubbed the Magus Cartam. During the revolutionary period, the Comstocks were supporters of Britain and were attacked; angry mobs burned down their estate and the family fled north to Canada. Ever since, the Comstocks have enthusiastically supported the Canadian Ministry; Edward James Comstock, a former Auror, even became Viceroy of Magical Affairs after the assassination of Andrew O'Leary in 1813.
A branch of the family began in South Africa after George Hamish Comstock, brother of William Cornelius Comstock, moved there in the turn of the century.