He and his descendants built and reconstructed several manor houses that are some of the most important sites of manorialism heritage in Lithuania.

On July 5, 1812, using his own funds, he began forming the 17th Lithuanian Uhlan Regiment, with his own initiative and money.

[2] In recognition, Napoleon named Tyszkiewicz the regimental commander with the rank of colonel and Chevalier of the Legion of Honour.

In 1811, after lengthy legal proceedings, he acquired the ruined Biržai Castle and dependent serfs from Dominik Hieronim Radziwiłł for 450,000 silver rubles.

[6] Palanga was developed as a seaside resort by his grandson Feliks Tyszkiewicz (1870–1932) who also built the current Tiškevičiai Palace.