What does it mean to practice international law? And how can the concept ‘knowledge of normativity’ help us gain deeper insights into this field? This blog post explores the SMS ‘Gazelle’ incident of 1864, in which a Prussian warship captured three Danish ships in the Bohai Sea off China’s coast. It is an incident that came to be credited as the first application of international law by China; but there is more to tell of this story.