Fourth in succession to the leadership of Chabad was Rabbi Shmuel, son of the Tzemach Tzedek. Rabbi Shmuel continued to spread the teachings of Chabad among the Jewish people, and at the same time to engage in communal activities to improve the spiritual and material conditions of the Jewish masses within and beyond the ranks of the Chassidic movement.

In 5615 (1855), at the age of twenty-one, Rabbi Shmuel’s father requested him to participate actively in communal work. Together with a colleague, Rabbi Shmuel traveled to the Russian capital in order to take part in a conference called by the Russian Government to discuss the problems connected with the publication of textbooks with a German translation for use in the instruction of Jewish children.

This conference was under the chairmanship of one of the assistants of the Minister of the Interior. Despite his youth, Rabbi Shmuel voiced his opinion clearly and vigorously to the officials of the Czarist Government.

Between the years 5616 and 5626 (1856-1866) he traveled extensively throughout the country and abroad, in order to meet and influence important Jewish leaders. The friends that he made and the confidence he inspired at these meetings were to be of great assistance to Judaism in later years.

After the death of the saintly Tzemach Tzedek in the spring of 5626 (1866), Rabbi Shmuel was elected to succeed him as head of the Chabad Chassidim. His leadership, which lasted from 5626 to 5643 (1866-1882), coincided with one of the stormiest periods of anti-Semitism in Russian history, originating in the highest circles of the Czarist court in St Petersburg. Many princes were among the violent Jew-baiters who constantly schemed to cause trouble to the Jewish communities and to instigate pogroms.

Rabbi Shmuel, keenly aware of his great responsibility, was among the foremost fighters in the battle for the survival and defense of the Jews. He was the moving spirit in all actions taken to save the Jewish masses or defend them against the vicious attacks from Government circles.

In 5629 (1869) Rabbi Shmuel organized a permanent council of leaders of the St Petersburg Jewish community. The council’s task was to be well-informed in all matters concerning the Jewish people and to be on constant guard to defend their interests and rights. From 5630 to 5640 (1870-1880), Rabbi Shmuel again made many trips to various parts of the Russian Empire and abroad, with complete disregard for personal safety.