Eriksson Vasa had been a prisoner in Denmark, sent there as a
hostage of Swedish loyalty. Having obtained his freedom by
flight, he made his way to the inland province of Dalecarlia,
where most of the previous movements on behalf of national
liberty had originated, and having cleared the country of foreign
invaders, chiefly by the help of an aroused peasantry that had
never known the yoke of serfdom, he was elected king at a Riksdag
held in the little city of Strangnas, not far from Stockholm, in
1523.

Strangnas was a cathedral city and had for several years previous
been notorious for the Lutheran leanings of its clergy. After the
death of its bishop as one of the victims of King; Christian, its
temporary head had been the archdeacon, the ambitious and learned
Lars Andersson--or Laurentius Andreae, as, in accordance with the
Latinizing tendency of the time, he was more frequently named.
One of its canons was Olof Pedersson--also known as Olaus Petri,
and more commonly as Master Olof (Master being the vernacular for
Magister, which was the equivalent of our modern Doctor)--who,
during two years spent in studies at the University of Wittenberg,
had been in personal contact with Luther, and who had become fired
with an aspiration to carry the Reformation into his native
country. By recent historians Master Olof has been described as
of a "naively humble nature," rather melancholy in temperament,
but endowed with a gift for irony, and capable of fiery outbursts
when deeply stirred. At Strangnas he had been preaching the new
faith more openly and more effectively than any one else, and he
had found a pupil as well as a protector in the temporary head of
the diocese.