Sergei Rachmaninov was born in 1873 in the Novgorod Governorate in the Russian Empire. His family was Russian aristocracy, and he was supposed to go into the army. That was what his father wanted and his family expected. His father was not very competent with finances though, and managed to lose the family assets. One by one he had to sell the land and as a result he was unable to afford the expensive education as an officer in the army.
The family also dabbled in music, and had contacts all over the place. It was noted that young Sergei was able to play long passages from memory without a single note wrong. So his grandfather suggested the family hired a teacher to teach him at home.
When he was just ten, Rachmaninov’s father left the family alone, and in two years time two of his sisters died. In this sad state of affairs Rachmaninov still managed to produce early works and finish his education at the conservatory. After that he fell in a long period of depression.
A depression was able to shake off around 1900. He got new musical ideas and inspiration. One of these was his second piano concerto, in 1901. The story about this I already covered in more detail here.