This article reconstructs the benevolent campaign mounted in London after the devastating Montreal fire of 1765. Appealing to a greater sense of British identity, the trustees framed the French Canadian sufferers as “new subjects” entitled to both imperial benevolence and Christian charity. At the core of the subscription were notable London philanthropist Jonas Hanway and Marine Society peers John Thompson and Fowler Walker. Well versed in the mechanics of a successful charitable subscription, the trustees employed a familiar Georgian strategy using a robust print and coffeehouse campaign to solicit public support. However, the trustees overestimated the public’s acceptance of their construction of a “greater Britain” and underestimated the elevated political enmity towards the British American colonies in the era following the Seven Years’ War. A lack of donor interest compelled them to enlarge their efforts and shift away from newer charitable tactics, instead embracing more traditional avenues such as gaining the patronage of King George III and engaging the greater British public through parish fundraising. This case study highlights the complexities of transatlantic benevolence and its use to push the boundaries of British identity in the mid-eighteenth century.