Swiss Swedish origin legend

In legend and in the early historiography of Switzerland there is an account of a migration of a population of Swedes and Frisians settling in the Swiss Alps, specifically in Schwyz and in Hasli ("Schwedensage").
Medieval legend.
The legend is discussed in Ericus Olai's "Chronica regni Gothorum" (c. 1470). Olai notes that the Swiss ("Svitenses") claimed to be descended from "Swedes or Goths". Olai also notes the similarity in toponymy, "Swycia, quasi Suecia". This is reflected in a late-15th-century gloss from Reichenau reading "Suecia, alias Helvicia, inde Helvici, id est Suetones."
A near-contemporary record is that of Petermann Etterlin, who wrote in the 1470s (printed as "Chronicle of the Swiss Confederation" in 1507).
Etterlin telling the legend refers to "the Swedes, who are now called the Switzer" ("die Schwediger, so man yetz nempt Switzer") presents an eponymous founder, one "Suit" ("Swit, Schwyt, Switer"), leader of the migrating Swedes, who defeated his brother "Scheyg" in single combat in a dispute over leadership of the new settlement.
He gives an account of their decision to settle on the site of Schwyz:
Etterlin's account is supposedly based on a "common Swiss chronicle" ("Gesta Suitensium", "gemeine Schwyzerchronik") also reflected in the White Book of Sarnen, Heinrich von Gundelfingen ("Das Herkommen der Schwyzer und Oberhasler") and later by Aegidius Tschudi ("Die Geschichte der Ostfriesen, Swedier und andre, so mit jnen gereisset, vnd wie Switer dem Lande den Namen Swiz gegeben"). 
Etterlin presents the three "Waldstätten" as representing three different stocks or races, the people of Schwyz as the most recent immigrants (from Sweden), the people of Uri representing the original "Goths and Huns", and the people of Unterwalden representing "the Romans".
Henrich von Gundelfingen gives an elaborate version of the legend, stating the emigration from Sweden and Frisia was due to a famine, which was met by king "Cisbertus of Sweden" by a decree that every month, the lot should be drawn and one in ten men would be forced to emigrate with all his family and possessions. Heinrich is the origin of the figures of 6,000 Swedes and 1,200 Frisians taking part in the migration with a certain "Suicerus" as their leader.
The legend is also mentioned by Albrecht von Bonstetten, a monk in Einsiedeln abbey, in 1479 ("Superius Germanie Confederationis descriptio"). In this version, the toponym "Schwyz" derives from a Swedish founder named "Switerus".
Sigismund Meisterlin (d. 1488) in his "Chronicon Norimbergense" claims the people of Schwyz as descendants of the Huns, with a leader called "Swifter" ruling the valley, while his brother "Senner" ruled the high pastures.
Records from the early 16th century confirm that the tradition was in fact part of local folklore (and not the result of learned etymological speculation); in an "Urner Tellenspiel" performed between 1511 and 1525, the identification of Gothic and Hunnic ancestry of Uri, Roman ancestry of Unterwalden and Swedish ancestry
of Schwyz,
and for the Landsgemeinde of Schwyz in 1531 we have the record of a performance of an "Andacht der Altvorderen" (remembrance of the forefathers) in memory of the "Austreibung aus Schweden" (eviction from Sweden) in times of famine.
The saga is also reflected in early-16th-century Frisian chronicles such as the "Tractatus Alvinus", Jancko Douwama's "Boeck der Partijen" and subsequent writings, as well as in the biography of the condottiere Wilwolt von Schaumberg from Thuringia, who led the conquest of Frisia by Albert of Saxony in 1498. According to the latter, 'the Frisians, when they write to each other, even nowadays, call the Swiss "son" and the Swiss call the Frisians "cousin".'
The first critical evaluation of the story is that of Tschudi in 1570, who is unsure if he should reject the account of Kiburger wholesale, or if the tradition might have a historical source in the Cimbri of 114 BC (unlike his 19th-century successors, Tschudi does not consider the possibility of a Viking Age migration).
Early Modern reception.
Once the legend had been written down in the late 15th century Swiss chronicles it became a standard topos of the early modern historiography of Switzerland. 
The legend did remain current in the folklore of Schwyz and Hasli in the 19th century, no doubt reinforced by historiographical and literary tradition. 
Schiller's "William Tell" (1804) makes reference to the legend (act 2, scene 2), in the voice of "Stauffacher". The Brothers Grimm included the legend in their "Deutsche Sagen" of 1818 (nr. 514 "Auswanderung der Schweizer"), and Ludwig Bechstein in his "Deutsches Sagenbuch" (1853) includes it as nr. 2 " Des Schweizervolkes Ursprung "). 
In Sweden, Uppsala historian Jakob Ek published an account of the legend in "De Colonia Suecorum in Helvetiam egressa" (1797).
Johannes von Müller in 1780 accepted that the foundational 
population of Schwyz was a separate race (i.e. separate from that of Uri and Unterwalden) and argued that this was still visible in the "exceptionally handsome" population of Oberhasli and the neighbouring Bernese Oberland as well as of Entlebuch.
Johann Georg Kohl (1849) also described the physiology of the people of Oberhasli as being of the Scandinavian type, as "remarkably tall, strong and blond".
Erik Gustaf Geijer in his "History of the Swedes" (1832–36) notes that the legend was now limited to the population of "Haslidale" but had once also been generally believed by the people of Schwyz. In this version, the Swedes march from a place called "Hasle" on the banks of the Rhine, defeating a Frankish army on the way, and settle in the alpine valleys because the landscape reminded them of their own country.
Geijer adds his opinion that the events would fall into the "age of the northern expeditions" (i.e. the Viking Age) of the 9th century. He cites a Viking Age chronicle which relates that in 861 a Viking expedition ascended the Mosel and wintered in a fortified camp at a place called "Haslow", defeated a Frankish army and moved onward pillaging along the Rhine.
Geijer equates this expedition with one mentioned in "Óláfs saga Tryggvasonar", in which the sons of Ragnar Lodbrok participated, advancing as far as "Wiflisburg" (Avenches) in Switzerland.
In 1846, Johann Georg Kohl travelled to Hasli, describing both its natural landscape and its population. Kohl recorded a tradition telling of a march of 6,000 Frisians and Swedes exiled from their homes by a famine. The names of the leaders of the immigrating Swedes is reported as "Restius" and "Hastus". Kohl describes the architecture of the Meiringen church as reminiscent of North Frisian and Scandinavian types.
The Hasli legend was received in Scandinavian Romantic nationalism, with e.g. Danish poet Adam Oehlenschläger publishing a poem "Haslidalen" in 1849.