Sicking is Aemilius Papinianus professor of History of Public International Law at Vrije Universiteit Amsterdam.

Recurring elements in Sicking‘s work are the French and Dutch language areas, as well as the lasting influence of the Middle Ages that extends into subsequent periods.

His thesis was published in English as Neptune and the Netherlands: State, Economy, and War at Sea in the Renaissance (2004).

[2] In this work, Sicking departs from a strictly Belgian or Dutch perspective, focusing instead on the origins of the Burgundian-Habsburg maritime organization in the broader context of the Netherlands.

[3] Serving as a lecturer of Medieval and Early Modern History at Leiden University since 2001, Sicking also holds an endowed chair in the history of international law at Vrije Universiteit Amsterdam since 2013.