Here's a short story:

The Åland Islands or Åland is an archipelago at the entrance to the Gulf of Bothnia in the Baltic Sea belonging to Finland. It is autonomous, demilitarised and is the only monolingually Swedish-speaking region in Finland. It is the smallest region of Finland, constituting 0.49% of its land area and 0.50% of its population. 

Åland comprises Fasta Åland on which 90% of the population resides and a further 6,500 skerries and islands to its east. Fasta Åland is separated from the coast of Sweden by of open water to the west. In the east, the Åland archipelago is contiguous with the Finnish Archipelago Sea. Åland's only land border is located on the uninhabited skerry of Märket, which it shares with Sweden. 

Åland's autonomous status means that those provincial powers normally exercised by representatives of the central Finnish government are largely exercised by its own government. 

The autonomous status of the islands was affirmed by a decision made by the League of Nations in 1921 following the Åland crisis. It was reaffirmed within the treaty admitting Finland to the European Union. By law, Åland is politically neutral and entirely demilitarised, and residents are exempt from conscription to the Finnish Defence Forces. The islands were granted extensive autonomy by the Parliament of Finland in the Act on the Autonomy of Åland of 1920, which was later replaced by new legislation by the same name in 1951 and 1991. Åland remains exclusively Swedish-speaking by this act. (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: is it bilingual?
Guess: No

Question: where do most of the people live?
Guess: Fasta Åland

Question: which country does it belong to?
Guess: Finland

Question: what is in the west of the Aland?
Guess: open water

Question: where is it located?
Guess: Baltic Sea

Question: is it just one island?
Guess: No

Question: where is it's land border?
Guess: on the uninhabited skerry of Märket

Question: does it share this with anyone?
Guess: Yes

Question: who?
Guess: Sweden

Question: when was it affirmed?
Guess: 1921

Question: who decided this?
Guess: League of Nations

Question: what had happened for this to be decided?
Guess: the Åland crisis

Now answer the following question in the same format.

Question: what happened in 1920?

the Act on the Autonomy of Åland