The outcome of the election was strongly contested by factions of the Polish nobility that supported the candidacy of Archduke Maximilian III of Austria, who briefly invaded the country.
Upon hearing of his election King Sigismund slipped through the clutches of the Protestants in Sweden and landed in Poland on 7 October, immediately agreeing to grant several royal privileges to the Sejm in the hope of winning over some of his opponents and settling the disputed election.
He was proclaimed by the Lesser Prussian Treasurer Jan Dulski as king on behalf of Crown Marshal Andrzej Opaliński, and after arriving in the Royal Capital City of Kraków he was crowned on 27 December at Wawel Cathedral.

Ultimately, Hetman Jan Zamoyski defeated Maximilian at the Battle of Byczyna and took him prisoner.
However, at the request of Pope Sixtus V, King Sigismund III released Maximilian, who surrendered his claim to Poland in 1589.
King Sigismund also tried to maintain peace with his powerful neighbor by marrying Archduchess Anne Habsburg in 1592.
It was always his intention to maintain an alliance with Catholic Austria against the Protestant forces.

When his father died King Sigismund III asked the Sejm to be allowed to claim his inheritance as the rightful King of Sweden.
The Poles had no objection.
When he promised to respect Lutheranism as the official religion of Sweden, the Swedes also agreed.
Sigismund was crowned King of Sweden in 1594.
He appointed his uncle, Duke Charles, to rule as regent on his behalf in Sweden while he remained in Poland, since Sweden and the Commonwealth were only in a personal union, not united in one state.
However, tensions grew quickly in Sweden, as despite his pledge, King Sigismund was a devout Catholic and this made the Swedes suspicious of their new ruler.
Lutheran firebrands warned that Sigismund had the ultimate goal of making Sweden Catholic again.
As proof they pointed to the Union of Brest set up in 1596, which brought the Eastern Orthodox people in Ruthenia into the Catholic fold and led to the modern day Ukrainian Catholic Church.
The union also expressed his friendship with Catholic Austria and his support for the Catholic Reformation, particularly the Jesuits, who were spreading out to refute Protestantism and regain lost spiritual ground for Rome.
The outcome of the election was strongly contested by factions of the Polish nobility that supported the candidacy of Archduke Maximilian III of Austria, who briefly invaded the country. Upon hearing of his election King Sigismund slipped through the clutches of the Protestants in Sweden and landed in Poland on 7 October, immediately agreeing to grant several royal privileges to the Sejm in the hope of winning over some of his opponents and settling the disputed election. He was proclaimed by the Lesser Prussian Treasurer Jan Dulski as king on behalf of Crown Marshal Andrzej Opaliński, and after arriving in the Royal Capital City of Kraków he was crowned on 27 December at Wawel Cathedral.
Ultimately, Hetman Jan Zamoyski defeated Maximilian at the Battle of Byczyna and took him prisoner. However, at the request of Pope Sixtus V, King Sigismund III released Maximilian, who surrendered his claim to Poland in 1589. King Sigismund also tried to maintain peace with his powerful neighbor by marrying Archduchess Anne Habsburg in 1592. It was always his intention to maintain an alliance with Catholic Austria against the Protestant forces.
When his father died King Sigismund III asked the Sejm to be allowed to claim his inheritance as the rightful King of Sweden. The Poles had no objection. When he promised to respect Lutheranism as the official religion of Sweden, the Swedes also agreed. Sigismund was crowned King of Sweden in 1594. He appointed his uncle, Duke Charles, to rule as regent on his behalf in Sweden while he remained in Poland, since Sweden and the Commonwealth were only in a personal union, not united in one state. However, tensions grew quickly in Sweden, as despite his pledge, King Sigismund was a devout Catholic and this made the Swedes suspicious of their new ruler. Lutheran firebrands warned that Sigismund had the ultimate goal of making Sweden Catholic again. As proof they pointed to the Union of Brest set up in 1596, which brought the Eastern Orthodox people in Ruthenia into the Catholic fold and led to the modern day Ukrainian Catholic Church. The union also expressed his friendship with Catholic Austria and his support for the Catholic Reformation, particularly the Jesuits, who were spreading out to refute Protestantism and regain lost spiritual ground for Rome.
Sigismund III Vasa