 This would mean that Tartessian is the earliest attested trace of Celtic by a margin of more than a century.The Canegrate culture represented the first migratory wave of the proto-Celtic population from the northwest part of the Alps that, through the Alpine passes, had already penetrated and settled in the western Po valley between Lake Maggiore and Lake Como (Scamozzina culture).It has also been proposed that a more ancient proto-Celtic presence can be traced back to the beginning of the Middle Bronze Age, when North Westwern Italy appears closely linked regarding the production of bronze artefacts, including ornaments, to the western groups of the Tumulus culture.