Poland was strictly an elective monarchy. The tumultuous nobles had established a law prohibiting the election of a successor during the lifetime of the monarch. Their last king had been the reckless, chivalrous Henry, Duke of Anjou, brother of Charles IX. of France. Charles IX. having died without issue, Henry succeeded him upon the throne of France, and abdicated the crown of the semi-barbaric wilds of Poland. The nobles were about to assemble for the election. There were many influential candidates. Maximilian was anxious to obtain the crown for his son Ernest. Much to the surprise of Maximilian, he himself was chosen king. Protestantism had gained the ascendency in Poland, and a large majority of the nobles united upon Maximilian. The electors honored both themselves and the emperor in assigning, as the reason for their choice, that the emperor had conciliated the contending factions of the Christian world, and had acquired more glory by his pacific policy than other princes had acquired in the exploits of war.
There were curious conditions at that time assigned to the occupancy of the throne of Poland. The elected monarch, before receiving the crown, was required to give his pledge that he would reside two years uninterruptedly in the kingdom, and that then he would not leave without the consent of the nobles. He was also required to construct four fortresses at his own expense, and to pay all the debts of the last monarch, however heavy they might be, including the arrears of the troops. He was also to maintain a sort of guard of honor, consisting of ten thousand Polish horsemen.
In addition to the embarrassment which these conditions presented, there were many indications of jealousy on the part of other powers, in view of the wonderful aggrandizement of Austria. Encouraged by the emperor's delay and by the hostility of other powers, a minority of the nobles chose Stephen Bathori, a Transylvanian prince, King of Poland; and to strengthen his title, married him to Anne, sister to Sigismond Augustus, the King of Poland who preceded the Duke of Anjou. Maximilian thus aroused, signed the articles of agreement, and the two rival monarchs prepared for war. The kingdoms of Europe were arraying themselves, some on the one side and some on the other, and there was the prospect of a long, desperate and bloody strife, when death stilled the tumult.