In 1905 in Mohylew, Russia, Blessed Boleslawa Lament founded religious congregation of Missionary Sisters of the Holy Family. Its goal was to work toward the unity of Orthodox Christians with the Catholic church. Also, the congregation was called to strengthen the faith of Catholics since their unity with the church was threatened in those times. Soon after, in 1907, the whole community of sisters moved to Petersburg. Sisters taught all children and youth despite their religion and nationality.

The first Constitution of the congregation, based on the thoughts of the Mother Foundress and St. Ignatius Spirituality, was confirmed by Archbishop Antoni Wnukowski and Archbishop Wincenty Kluczynski. It was done orally because the political situation would not allow otherwise. The Archbishops gave sisters a permission to live as a community. The life of the community was supposed to be based on Congregation's constitution.