With no explanation, label each line with "building-other", "O", "organization-other", "person-politician", "location-GPE", "art-broadcastprogram", "art-film", "art-music", "art-other" or "art-painting" preceded by ":".
When
King
Gustav
Vasa
broke
Sweden
free
from
the
Kalmar
Union
(
a
series
of
personal
unions
between
Denmark
,
Sweden
and
Norway
since
1397
)
and
made
Sweden
independent
again
,
Tre
Kronor
Castle
became
his
most
important
royal
seat
.
When:O
King:O
Gustav:person-politician
Vasa:person-politician
broke:O
Sweden:location-GPE
free:O
from:O
the:O
Kalmar:organization-other
Union:organization-other
(:O
a:O
series:O
of:O
personal:O
unions:O
between:O
Denmark:location-GPE
,:O
Sweden:location-GPE
and:O
Norway:location-GPE
since:O
1397:O
):O
and:O
made:O
Sweden:location-GPE
independent:O
again:O
,:O
Tre:O
Kronor:building-other
Castle:building-other
became:O
his:O
most:O
important:O
royal:O
seat:O
.:O