The white grape variety originates from the border region Italy/Switzerland. Synonyms are Großer Lafnetscha, Kleiner Lafnetscha, Lindauer, Malans, Malanserrebe, Malanstraube, Malansertraube, White Malanstraube and Zürirebe. The variety is mentioned as early as 1321 in a document of the cathedral of Chur (according to another source already in 926). The name of the wine of the same name is derived from the evening prayer "Completorium", according to which the strong wine was formerly drunk by the monks of the cathedral chapter of Chur during Lent as refreshment.
The parents of the variety are unknown. It is said that the variety was imported from Italy to Malans in the canton of Graubünden by Benedictine monks of the Pfäfers monastery in St. Gallen. The Italian origin is supported by the fact that there are family relations between Completer and the Italian varieties Marzemino and Pignolo Spano. In Switzerland, Completer is classified in the Old Growths grape variety group. The ancestry of some of these varieties has been clarified by several DNA analyses. Lafnetscha is the result of a presumably natural cross between Completer and Humagne Blanche. The varieties Bondoletta and Hitzkircher were created from crosses between Completer x Bondola.