What is "aubaine"

Aubaine \Au`baine"\, n. [F., fr. aubain an alien, fr. L. alibi elsewhere.] Succession to the goods of a stranger not naturalized.
--Littr['e].

Droit d'aubaine, the right, formerly possessed by the king of France, to all the personal property of which an alien died possessed. It was abolished in 1819.
--Bouvier.

n. (context historical legal English) succession to the goods of a stranger not naturalized

In old French customs, aubaine (, windfall) was the inheritance of goods from a foreigner who died in a country where he was not naturalized. The word is formed from aubain, a foreigner, which Gilles Ménage derived further from the Latin alibi natus; Jacques Cujas derived from advena; and du Cange from albanus, a Scot or Irishman, by the reason that these were anciently frequent travelers living abroad.

In the Ancien Régime, aubaine was a right of the King of France, allowing him to claim the inheritance of all foreigners in his dominions; exclusive of all other lords, and even of any testament the deceased could make. An ambassador, though not naturalized, was not subject to the right of aubaine. The Swiss, Savoyards, Scots, and Portuguese were also exempted from aubaine, as they were considered naturalized.