Each June 16, Sikhs commemorate the 1606 martyrdom of Guru Arjan Dev Ji, the fifth guru and the first Sikh martyr. Guru Arjan Dev compiled past Gurus' writings into the book that became the scripture, the Guru Granth Sahib. The Muslim emperor ordered him to remove Hindu and Islamic references from the book, which the Guru refuse to do. As this site explains, Guru Arjan experienced five days of torture, then he disappeared into the river into which he was allowed finally to bathe. His martyrdom became a turning point for Sikhs, who thereafter became prepared to defend their independence. His son, the sixth Guru, Guru Har Gobind Ji, wore two swords representing both spiritual and temporal power and began to train Sikhs as an armed force.