The paper focusses on a peculiar but so-far neglected theme in the modern-age history of the relationship between the Hungarian Kingdom, the Habsburg Monarchy and the Ottoman Empire: the Hungarian costumes of the Habsburg envoys delegated to the Porte in the 17th century. The highest ranking representatives of the diplomacy of the Habsburg House mostly of West European family ties and traditions – the overwhelming majority of whom had no Hungarian connections at all – wore ornate Hungarian costumes for their official appearances in Constantinople. It is self-evident to wonder: Why did the Habsburg House resort to this solution? and What conclusions of broader relevance can be drawn from the phenomenon? Based on archival researches in archives in Austria and Hungary, the outfit of the envoys can be reconstructed including the particularly accented dolman, fur-lined short coat mente and the Hungarian hat, while the uniquely detailed documentation of the legation of Johann Ludwig Kuefstein also sheds light on who and where produced each item. The research concluded that the Hungarian costume had an emphatic role not only in the relationship between the Habsburg monarchs and the Sublime Porte based on a complex system of symbols, but was also part of the communicational strategy toward the Hungarian estates, for it was manifestation of the exclusive and legitimate but repeatedly questioned domination of the Hungarian Kingdom by the Habsburgs toward both the dignitaries of the Porte and the Hungarian elite.