This thesis traces Elizabeth Posthuma Simcoe's (1766-1850) changing relationship to landscape during her stay in Canada (1791-1796), as she transformed from a genteel watercolour painter of tamed British landscapes to practicing less conventional means of creativity, which resulted most spectacularly in her developing an aesthetic fondness for setting forest fires. This thesis proposes that above and beyond Simcoe's painting, her art practice can also encompass this alternative means of aesthetic expression in relation to landscape.  Simcoe's practice, as such, conceptually parallels ideas running through late eighteenth-century European culture, specifically philosophy and art practice, concerned with the state of picturesque and sublime landscapes. Mirroring this discourse, Simcoe's performative behaviour and creative practice illustrate a subtle but marked shift from a removed picturesque appreciation of landscape, to an active creation of a sublime experience within the landscape, as she grapples with the colonial space in which she temporarily resides. When this transition in Simcoe's performativity and practice is analysed through contemporary theory on postcolonial landscape, female subjectivity and performativity, and the feminist sublime, an intriguing narrative begins to emerge of a woman facing, and then working within and for, the breakdown of conventional cultural systems through visual metaphor.