Pyotr Ilyich Tchaikovsky wrote his Symphony No. 1 in G minor, Winter Daydreams (Russian: Зимние грёзы, Zimniye gryozy), Op. 13, in 1866, just after he accepted a professorship at the Moscow Conservatory: it is the composer's earliest notable work. The composer's brother Modest claimed this work cost Tchaikovsky more labor and suffering than any of his other works. Even so, he remained fond of it, writing to his patroness Nadezhda von Meck in 1883 that "although it is in many ways very immature, yet fundamentally it has more substance and is better than any of my other more mature works." He dedicated the symphony to Nikolai Rubinstein.
The symphony is scored for piccolo, two flutes, two oboes, two clarinets (A, B-flat), two bassoons, four horns (E-flat, F), two trumpets (C, D), three trombones, tuba, timpani, cymbals, bass drum and strings.
Tchaikovsky started writing this symphony in March 1866. Work proved sluggish. A scathing review by César Cui of the cantata he had written as a graduation piece from the St. Petersburg Conservatory shattered his morale. He also composed day and night. All these factors strained Tchaikovsky's mental and physical health tremendously. He started suffering from insomnia, from pains in his head which he thought to be strokes, and became convinced he would not live to finish the symphony. A successful performance of his revised Overture in F in St. Petersburg lifted his spirits. So did a change of scene for the summer with his family. Nevertheless, he soon worked himself again into nervous and physical exhaustion by continuing to compose day and night. A doctor declared him "one step away from insanity," ordering complete rest. Tchaikovsky complied.