^{page 111 note 1} A fuller narrative of their relationship than that which follows may be found in my book Bride of the Revolution: Krupskaya and Lenin (Ann Arbor, Michigan and London, 1972). This work provides source references concerning the particulars that follow in this introductory note.

^{page 112 note 1} See second paragraph of the following document.

^{page 113 note 1} The present writer is greatly indebted to the Harvard University Library and the late Merle Fainsod for permission to publish the text of this letter. It bears the Trotsky Archive number T950.

^{page 113 note 2} Harvard University, Trotsky Archive number T951.

^{page 117 note 1} In Trotsky's handwriting to this point.

^{page 117 note 2} This letter is lost or inaccessible.

^{page 117 note 3} S. V. Kosior (ancient spelling Kassior) was a rising Stalinist in the mid-twenties, a member of the Central Committee and Secretariat. The Central Committee plenum at which he spoke of a “fuss” must have been that of April 13–16, 1927. No resolutions of this plenum dealing with the disputed issue are available, but the communiqué of the meeting (Pravda, April 19, 1927) states that it “heard and considered the Politburo communication concerning the decisions that it adopted in connection with recent international events (events in China and others)”.

^{page 117 note 4} The “electoral instructions” may be the party resolution “On the Re-election of Soviets”, in: Spravochnik partiinogo rabotnika, Vol. 6, Part 1, p. 631. The slogan “enrich yourselves” was proposed by N. I. Bukharin in April, 1925 with respect to the peasants under the New Economic Policy.

^{page 118 note 5} This is an allusion to the famous “Postscript” to Lenin's testamonary letter. See Lenin, Sochineniia (4th ed.), pp. 545–546.

^{page 119 note 6} The last sentence was inscribed in Trotsky's hand. In his draft he originally continued the sentence: “and equally unshakable confidence in the Tightness of the line that you will defend.” Evidently he had second thoughts on this, because he crossed out the words following “health”. Was it that his confidence concerning Krupskaya's choice of lines was all too shakable?