Born in Tryavna during the Bulgarian National Revival under Ottoman rule, Pencho was educated there as well as in Stara Zagora and Plovdiv.

After an accident in January 1884, when at the age of eighteen he fell asleep on a bench while it was snowing and thus he fell ill with pneumonia, and despite lengthy treatment in Plovdiv, Sofia, Leipzig, Berlin and Paris, this illness left him with serious impairments – he could not walk without a cane, and he wrote and spoke with difficulties.

He collaborated with a number of magazines, which issued his works, and spent a part of his life in Leipzig studying philosophy, where he became familiar with German literature, thought and art.

After returning to Bulgaria in 1898, Slaveykov joined the Misal circle with a number of other noted writers, such as Krastyo Krastev, Petko Todorov and Peyo Yavorov.

He was fired from the post of director of the National Library because of political misunderstandings with the minister of culture Stefan Bobchev on 10 July 1911, and left Bulgaria, living in Zürich, Lucerne, Göschenen, Andermatt, Lugano and other places in Switzerland before arriving in Italy in the end of November 1911.