Sankardeva preached a monotheist form of Hinduism called Vaishnavism and established monasteries and hermitages known as satra on the islet .
Sankardeva is a pioneer of the medieval - age neo-Vaishnavite movement .
Sankardeva , a pioneer of the medieval - age neo-Vaishnavite movement , preached a monotheist form of Hinduism called Vaishnavism and established monasteries and hermitages known as satra on the islet .