Lu
Lu is a member of the League of Lost Languages, spoken by a group often misidentified as Gypsies, who have run around in circles for about the past thousand years, first leaving Central Asia, then getting kicked out of the Papal States, then Galicia, then Oujd in modern Morocco, then Sicily, and most recently Naples (during the late 1700s).
Lu is an Indo-European language, with a linguistic history independent of any other. It bears a passing resemblance to both Tocharian and the various Indo-Iranian languages. It has seen extreme influence from Turkic languages and Moroccan Arabic, in addition to more recent French influence. Much of the religious idiolect is a mixture of Sanskrit and early Italian loans.
As Lu wasn't written down until the 1960s, its orthography is wonderfully regular.