Yes, the Sikh Gurus actively opposed the caste system. Sikhism, founded by Guru Nanak in the late 15th century, emphasized the equality of all individuals regardless of caste, creed, or gender. Guru Nanak and subsequent Gurus preached against the discrimination and social stratification perpetuated by the caste system.
The teachings of the Gurus promote the idea of a universal brotherhood and emphasize that one's worth is determined by actions and spiritual devotion rather than by caste lineage. The Sikh scripture, the Guru Granth Sahib, includes hymns that challenge the validity of caste distinctions and advocate for social justice and equality.
Moreover, practices such as the sangat (community assembly) and the langar (community kitchen) reflect the Sikh commitment to egalitarianism, as they encourage individuals from all backgrounds to sit together, share meals, and participate equally in religious and community life. These principles were integral to Sikh identity and doctrine, reinforcing the rejection of caste-based discrimination.