By the time of his death William Conolly was an exemplar of the Irish Protestant ascendancy. He had established a dynasty that would survive into the twenty-first century, and whose power, wealth and status in the eighteenth century was symbolised by his country house, Castletown. His political career had been devoted to maintaining the ‘Protestant interest’ cemented by the victories on the battlefields of Aughrim and the Boyne. These victories had created the opportunity for Conolly to prosper in a manner that would have seemed impossible at the time of his birth in 1662. After all, he was not born with the inherited advantages traditionally associated with the ascendancy. Instead he had created his own place within the Irish elite through ability, hard work and devotion to the maintenance of the ‘Protestant interest’. In doing so he had brought his family from provincial obscurity into the first rank of the Irish gentry.

The Conolly family history, in all major published genealogical sources, begins with William Conolly adding to the view expressed by one contemporary commentator that he was one ‘whom fortune in a frolicsome mood raised from the lowest of the people to make him equal to the peers of the realm’. The influence of ‘fortune’ is perhaps overstated, but Conolly certainly had risen from provincial obscurity, so much so that many of the details about his family background are contested, or are the subject of conjecture. He was born in Ballyshannon, County Donegal, in 1662, although the precise date is unknown. He was the eldest son of Patrick and Jane Conolly. Patrick Conolly has been variously described as a miller, innkeeper, or blacksmith. He was almost certainly the Patrick McConnelly recorded as paying tax on two hearths in Ballyshannon in 1663 and also the Patrick O’Conolly recorded as paying £10 on the subsidy roll for Kilbarron, the local Church of Ireland parish, in 1662. The different variants of the spelling of his name point towards a gradual anglicisation of their name, possibly connected to conversion to the established church. The sums recorded on both the subsidy and hearth tax rolls were, however, substantial and suggest that Conolly senior enjoyed some prominence in the local community.