1851 - Izrael Kalmanowicz Poznanski marries Leonia Hertz, who is dowered with „materials trade (shop)”, worth 750 roubles. This marriage enriches Izrael Poznanski’s, a master of „weaving profession” at the time, fortune by a manufacture worth 500 roubles,

1877 - He buys a building plot on the corner of Ogrodowa and Zachodnia streets with a one-storey house, which is to become the basis for the largest future palace residence in Łódź – he built the most beautiful factory building of the textile works along Ogrodowa street equipping it with 3600 spindles

1900 - His wealth exceeds 11000000 roubles. The same year he dies and his eldest son, Ignacy, takes over the business.

1902/3 - construction of Poznanski's palace is finished.