Excerpts from Books and Wikipedia
"The nine Gurus who followed Nanak further developed the Sikh religion in the face of often brutal persecution by the Mughal leaders of India. The final Guru, Guru Gobind Singh, died in 1708. He was succeeded by the Sikh Holy Scripture, the Guru Granth Sahib, which had been set down in his lifetime and became the perpetual Guru of Sikhism." [Furtado: 1001 Days]