In 1789, Edmund Armstrong bought Forty Hall and the associated grounds for £8,800.

The Armstrong family originated from Garry Castle in Ireland. As a younger son, Edmund made his living acting as an army agent and as a collector of customs duties in Barbados. Keen to make Forty Hall his own, he removed both the Rainton and Wolstenholme crests from the building and is believed to have built an entrance lodge with gates at the end of the driveway.

The Armstrong family did not reside at Forty Hall for very long. Edmund’s son William inherited the Hall in 1797, but was forced to sell the Estate in order to settle his father’s debts.