After the First Partition of Poland-Lithuania and the second Suppression of the Society of Jesus (1773) he became the right hand man of Vicar General Czerniewicz, negotiating alongside him the survival of the Jesuits with Empress Catherine II of Russia, all the while making sure that the standard of scientific education in Polotsk remained high.
Lenkiewicz was busy preparing the Second General (Interim) Congregation called to elect a successor to Stanislaw Czerniewicz (died in 1785) when news reached him that Pope Pius VI had given verbal approval (12 March 1783) for the existence of the Society in Russia.
He developed missionary activities in the North, but had to struggle to maintain the Society’s independence in the face of interference from the local bishop.
The years when Lenkiewicz was Vicar General were characterised by improved stability in the life of the Jesuits in Russia, and by the renewal of apostolic activities.
Spending 30 years in Polotsk in various capacities Lenkiewicz made it a renowned place, with its scientific laboratory, rich library, museum of natural sciences, and other artistic and religious resources.