evidence: Ireland, the UK, Iceland and Denmark (on behalf of the Faroe Islands) have made competing claims to marine jurisdictions around Rockall since the UK purported to ‘annex’ the rock in 1955. In this post I focus on the core of the current dispute between Ireland and the UK, which is the UK claim to territorial sovereignty over the rock that is now being vigorously asserted by Edinburgh. Although in the past it has claimed different categories of marine jurisdiction around Rockall, Ireland has not to date articulated a territorial claim to the rock itself. Based on research into Irish state practice in relation to the dispute, I argue it has nonetheless not foreclosed the possibility of making a territorial claim and should now change strategy and do so. If Ireland were to make such a claim, I argue the current UK claim would be a weak one from the perspective of relevant principles of customary international law on the acquisition of territory.