Srila Kedarnatha Datta Thakura Bhaktivinoda (1838-1914), the "grandfather" spiritual master of
Bhaktivedanta Swami (i.e. he was Prabhupada's Spiritual Master's spiritual master), but incidentally his father. The spiritual master of Srila Gaurakishora dasa Babaji Maharaja, and father of Srila Bhaktisiddhanta Sarasvati, he will be most remembered in Vaishnava history
for his against the derogatory attitudes of British imperialists toward Vedic
culture (which were often adopted by his contemporaries) and the
misrepresentation of Vaishnavism by the sahajiyas(*) (who do not
follow regulative principles). He authored many books on the philosopy and teachings of Lord
Caitanya Mahaprabhu as well as devotional songs (bhajanas)
collected into books like Saranagati, Gitavali, etc.
(*) See Sahajism and prakrita-sahajiya.