Joachim I Nestor, the eldest son of John Cicero, Elector of Brandenburg, had received an excellent education under the supervision of Dietrich von Bülow, Bishop of Lebus and Chancellor of Frankfurt University.
Becoming Elector of Brandenburg upon his father's death in January 1499, he soon afterwards married Elizabeth of Denmark, daughter of King John of Denmark.
They have five children: Joachim II Hektor, Anna, Elisabeth, Margaret, and John.
Joachim has taken some part in the political complications of the Scandinavian kingdoms, but the early years of his reign had mainly been spent in the administration of his electorate, where he had succeeded in restoring some degree of order through stern measures.
He has also improved the administration of justice, aided the development of commerce, and is sympathetic to the needs to the towns.
On the approach of the imperial election of 1519, Joachim's vote is eagerly solicited by the partisans of King Francis I of France, and Charles of Burgundy.
Having treated with both parties, and received lavish promises from them, he appears to have hoped to be Emperor himself; but when the election comes, he turned to the winning side and votes for Charles.
In spite of this, relations between the Emperor and the Elector are not friendly, and during the next few years Joachim will frequently be in communication with Charles' enemies.
In the course of Hohenzollern power politics Joachim Nestor and his brother had managed to get the latter, Albert of Mainz, first onto the sees of Magdeburg and then its suffragan of Halberstadt, both prince-bishoprics also comprising princely territories.
Since prince-episcopal sees are so influential, competing candidates usually run for them.
A candidature can turn into a bribery competition, without ever knowing exactly how much competitors pay to obtain office.
The expenditures involved, as far as they exceed one's own potential, are usually advanced by creditors and have then to be recovered by levying dues from the subjects and parishioners in the prince-bishoprics and dioceses that have just been acquired.
The acquisition in 1514 of the very influential Prince-Archbishopric-Electorate of Mainz for Albert was a coup that had provided the Hohenzollerns with control over two of the seven electoral votes in imperial elections and many suffragan dioceses to levy dues.
According to canon law, Albert was too young to hold such a position and since he would not give up the archiepiscopal see of Magdeburg (in order to terminate the accumulation of archdioceses, which was also prohibited by canon law), the Hohenzollerns had to dispense ever greater briberies at the Holy See.
This had exhausted their means and caused them to incur vast debts with the Fuggers.
To assist in the recovery of the enormous expenditures employed to assist Albert, mediators stipulate with the Holy See that the pope will allow Albert to sell indulgences to the believers in his archdioceses and their suffragans.
The sales proceeds have to cover the amortization and servicing of the debts; a share for the Holy See, for allowing this exploitation of the believers; the expenditure paid from the Hohenzollerns’ own pockets; and the charges involved with the sales.
The neighboring Electorate of Saxony also bid for the See of Mainz, but failed to secure it.
The Saxon elector Frederick the Wise had debts of his own as a result, but no see to show for it and no privilege to sell indulgences to recover his expenditures.
Frustrated, he has forbidden the sale of indulgences in his electorate and allowed Martin Luther to polemicize against them.
Joachim Nestor, in contrast, has become known as a pugnacious adherent of Roman Catholic orthodoxy who needs the sales of indulgences and the necessary intimidation of the believers in order to recover his expenditures.
Joachim Nestor's brother, Archbishop Albert, is the initial object of Luther's attack.
He urges on the Emperor the need to enforce the Edict of Worms, and at several diets is prominent among the enemies of the Reformers.
