In ancient Persia, the most admired sweet was ground almond paste. Typically it was flavored with rose water and formed into finger-sized rolls and then, for an extra treat, wrapped in a paper-thin pastry made from egg whites and cornstarch.
When the Arabs conquered Iran, lauzinag suavely went on to become the most admired dessert in Baghdad. A 10th century poet compared it, inevitably, to "a bride's fingers swathed in delicate veils." Plain almond paste is still around in the Middle East, where it's now called lauzina, but it has to take a back seat to filo pastries like baklava (themselves, ironically, often filled with almond paste).
Lauzinag also reached Europe by way of Spain. But in Spain, the Moors started calling it by a new name, makshshaba^an, which was the name of the kind of wooden box they stored it in. In Spanish, that word became mazapan. Other Europeans heard the Spanish name and thought it meant "March bread," which is why our name for it (by way of German) is marzipan.
Lauzinag wasn't the only ancient Persian sweet to have the ending -inag, by the way. Another was vafrinag, which got its name because it was so white ("vafr" was the Persian word for snow). Vafrinag eventually spread to India, but by the time it did, the Persians had taken to pronouncing their word for snow differently, and that's why in Indian restaurants you sometimes find a sweet with the unfortunate name barfi. Keep telling yourself that barfi really means "as white as snow."