Eventually, amidst increasing political rivalry with other nobles and mounting debts, Tyzenhauz was accused of fraud and removed from public offices in 1780.
After the election of Poniatowski to the throne of Poland–Lithuania (1764), Tyzenhauz became Court Treasurer of the Grand Duchy of Lithuania, the Starosta of Hrodna, and administrator of royal estates.
Tyzenhauz was in charge of all matters related to the land possessions of the King of Poland and exercised considerable freedom in their management.
In Šiauliai he attempted to create royal folwarks by taking land from serfs, demanding two days of corvée, increasing rent payment in cash, and adding additional duties (such as road building).
Inspired by the Age of Enlightenment he also opened schools for midwives, physicians, veterinarians, accountants, engineers, even ballet dancers.
[6] In Hrodna, his main residence and centre of his economic initiatives, Tyzenhaus built 85 structures and planned an entire borough, named Horodnica (derived from craftsmanship).
Tyzenhauz built the Tyzenhaus Palace in Vilnius (converted into an apartment building by the Soviet authorities) and another residence in Hrodna.