Francis I succeeded his father in 1543 as duke of Saxe-Lauenburg, but resigned in favour of his major son Magnus II in 1571.
With his thriftiness Francis I deeply plunged Saxe-Lauenburg into debts, to this end he pawned most of the ducal demesnes to his creditors.
[1] In 1550 Francis I wielded his influence to make the chapter of the neighbouring Prince-Bishopric of Ratzeburg elect his 7-year-old son Magnus as coming prince-bishop, however, the capitular canons refused.
In 1558 he conquered the prince-episcopal Bridgettine Monastery of Marienwohlde near Mölln, looted and demolished the cloister, forced its vassal farmers to swear him loyalty and pay him dues, and started overfelling in the monasterial woods, selling the timber abroad.
[4] This severed the anyway difficult relations with the estates of the duchy, which fought the ducal practice of growing indebtedness.