Trailblazers’ wakes: Ship tracks in Western imperial mapping

In the chapter of his Commentary on the Law of Prize and Booty that he published, anonymously, as the pamphlet Mare Liberum, the seventeenth-century jurist Hugo Grotius made an apt point: 'If, on the other hand, the Portuguese describe as ‘occupancy’ the acts of navigating at an earlier date than other peoples and of more or less opening the way, what contention could be more absurd? For there is no part of the sea upon which someone has not been the first to enter, so that it would necessarily follow from such a contention that every navigable region had been ‘occupied’ by some voyager. Thus we should be excluded from all parts of the sea. Indeed, it would even be necessary to admit that the [earliest] circumnavigators of the globe had acquired for themselves the whole Ocean! But no one is ignorant of the fact that a ship sailing over the sea no more leaves behind itself a legal right than it leaves a permanent track.' I argue that this controversial function – personal occupation of the otherwise unmarkable – is key to the development of the track line in the West. I also believe, for this reason, that the sea is the central pillar of this story, and more specifically the colonial overseas activities of Western European states, from the late fifteenth century onwards. This is the core argument of my book, Tracks on the Ocean, forthcoming with Profile Books. In this short piece, I summarise three points: the apparent aversion of ancient and medieval mapmakers towards graphic representation of maritime itineraries; the origins of maritime journey tracks in the early sixteenth century; and the peculiar functions that they acquired in the context of Western imperial expansion.British Academy Postdoctoral Fellowship (PF22\220060)