Franz von Hatzfeld was born in Crottorf, near Friesenhagen, on 13 September 1596, the third son of Freiherr Sebastian von Hatzfeld-Wildenburg (1566-1631) and his wife Lucia von Sickingen (1569–1605), a granddaughter of Franz von Sickingen. His elder brother was Melchior von Hatzfeldt, Imperial field marshal. His father had been raised a Protestant, but converted to Roman Catholicism.
In 1615, he became a canon of Würzburg Cathedral and, two years later, of Bamberg Cathedral. At age thirty, he became head cantor of Bamberg Cathedral, and the next year, became diocesan administrator of Würzburg. He then served as provost of the Gangolfskirche in Bamberg.
With the Thirty Years' War raging, Swedish troops occupied the Prince-Bishopric of Bamberg and Franz von Hatzfeld fled to Cologne as a protective measure. On 20 June 1633 Lord High Chancellor of Sweden Axel Oxenstierna declared that the Prince-Bishopric of Bamberg and the Prince-Bishopric of Würzburg would henceforth be combined as the "Duchy of Franconia" and enfeoffed to Bernard of Saxe-Weimar.
On 4 August 1633 the cathedral chapter of Bamberg Cathedral (which had escaped to the Duchy of Carinthia) elected Franz von Hatzfeld Prince-Bishop of Bamberg, with Pope Urban VIII confirming this appointment on 31 October 1633. This created a personal union between the Prince-Bishopric of Würzburg and the Prince-Bishopric of Bamberg.
|Catholic Church titles|
Philipp Adolf von Ehrenberg
| Prince-Bishop of Würzburg
Johann Philipp von Schönborn
Johann Georg Fuchs von Dornheim
| Prince-Bishop of Bamberg
Melchior Otto von Voit von Salzburg