Below, we present an excerpt from a letter by the Rebbe Shlita written to one of his rabbinic sons-in-law, referring to the essay "Fathers of Chassidus," which he wrote while he resided in Marienbad. [The letter is dated] 23 Menachem Av 5691 [August 6, 1931].

...regarding your inquiry about the history of Toras Chassidus Chabad, its establishment, development, and dissemination:

My first thought was that the preparation of an essay on this important and lofty subject could be more easily undertaken if I were at home, where I could use the resources of my library of sacred manuscripts.

However, I was also aware of the busy daily routine I keep at home, and the large amount of work I am burdened with. What would most likely occur upon my fortunate return home, is that I would be beset by my usual daily schedule, and I would not find the time for this job.

Consequently, I deemed it better to write at least a few lines, containing a general overview of the seven generations of the Fathers of Chassidus, representing the seven "Branches of the Chassidic Menorah." This may then serve as the mortar and bricks from which a finished essay on our subject could later be constructed.

I chose a quiet nook that afforded privacy from the tourists hiking around the hills of Marienbad. This spot was furnished with a table and a chair. I wrote for six or seven hours each day, until (with G-d's help) I managed to compose a brief outline of the history of the establishment of Toras Chassidus Chabad, its expansion, and its dissemination....