“One ship after the other landed in the bays and discharged its cargo of people, animals and goods” – this is how Matts Dreijer has described what he called The Great Colonization wave to the Åland islands in the middle of the 6th century AD. And although there are different nuances in the interpretations, in general, the researchers seem to have an agreement that there was a rapid population growth due to large-scale colonization to Åland in the beginning of the Late Iron Age (LIA), which, furthermore, was preceded by the long period of settlement decline during the Early Iron Age (EIA).

Paining by Tom Lovell (Vikings land at Vinland in Newfoundland) is just perfect to illustrate Dreijer’s concept of The Great Colonization wave. From http://americangallery.wordpress.com/2012/12/22/tom-lovell-1909-1997/vikings-land-at-vinland-on-newfoundland/
In fact, colonization to Åland was hypothesized already in the middle of the 19th century by Karl August Bomansson – the first scholar ever dealing with the archaeology of the Åland islands. Emanating from his studies on LIA grave mounds, Bomansson suggested that Åland was gradually populated and from several different territories of Sweden. Also after Bomansson, more than one region in Sweden has been suggested as the place of origin for the new population of Åland in the beginning of LIA (f.ex. by M.Dreijer, but also by A. Hackman, M. Núñez and J. Callmer), while Mälaren area in the eastern middle Sweden is considered to have had the greatest cultural impact. Ella Kivikoski is an exception in this connection, because her investigations suggested early colonization from Finland. There are also researchers (such as B. Roeck Hansen) who suggest this early colonization from both Sweden and Finland. Basically, the only researcher very-very carefully questioning if there was colonization at all in the beginning of LIA is Jan-Erik Tomtlund; unfortunately, he does neither motivate nor discuss his skepticism in this regard.
No matter the suggested direction of the colonization or the actuality of the colonization in the beginning of LIA, Viking Age on Åland is uniformly agreed to have been dominated by Swedish population and culture. But in the very beginning of the 11th century something quite remarkable occurs on Åland when compared to the Baltic Sea region in general – around the year 1000 traditional archaeological source material just disappears for a number of years. And that has puzzled the researchers; no consensus exists and quite a variety of explanations has been suggested. Settlement discontinuity and early medieval re-colonization have been hypothesized, especially by place-name researcher Lars Hellberg whose research triggered rather lively discussion arguing for the opposite. Also, settlement regression has been suggested as well as cultural transgression (f.ex. by Núñez and Roeck Hansen). Then, Dreijer has strongly argued for the early Christianization of Åland that would explain the disappearance of the traditional archaeological source material, and, for example, Tomtlund considers that to be a possibility, while Kivikoski has always neglected Dreijer’s idea of the early Christianization.
To sum up, there are four interesting aspects that seem to characterize the published state and, thereby, our current understanding of the Iron Age on the Åland islands: 1) settlement decline during EIA, 2) colonization in the beginning of LIA, 3) domination of Swedish population and culture during Viking Age, and 4) abrupt disappearance of the traditional archaeological source material in the end of LIA.