Allasia is quite widespread between Cuneo and Turin, Allasio, much rarer is typical of Turin, should derive from the original name of the Languedoc Alas which became Alasius in Latin, of this surname there are traces for example in the Cuneo area in 1500, in an act between one can read: "... Iohannis Francisco Romano, Iohannis de Alasio testibus ad omnia supradicta vocatis et rogatis.". I performed a research (method on baptism and marriage proceedings in different churches in the provinces of Turin and Cuneo recording everything, even the collateral branches and some strains that did not belong to mine, I also visited the historical archives of Turin, Cuneo, the Savoy Library of Turin and the historian of Sommariva Bosco, where, as per copies of documents in my possession, there were at least 15/20 families Allasia / Alasia already around 1400 with the oath made to the Savoy. Alasia is one of the important noble surnames of the the city of Cuneo since its foundation in the 12th and 13th centuries It may be that the origin is due to the fact that the ancestor served an important person with the name of woman: Adelasia, Alasia or that as you have exposed by Alas, who during the Latin plural recordings (son of father and mother) became de Alasis or de Alasys, understood as spouses, who turned back to death or other declarations still transformed into Alasia. lasia and Alasia are the same thing, the origin pressed could be traced back to Alasia, during church recordings (until 1806 when Napoleon established the cemeteries and the municipal registry) starting from the Council of Trent in 1541, both for my strain that for the others I have documented recordings, initially Alasia, that then varied in Allasia, again Alasia (my great-grandfather was born Alasia, deceased Allasia, his deceased father Alasia, born Allasia, his father still was Alasia as those who had preceded him, I also noted documents that record de Alaysis arriving or returning to the French Riviera.
You may be interested
Verba Volant, Scripta Manent