Spinoza also corresponded with Peter Serrarius, a radical Protestant and millenarian merchant. Serrarius was a patron to Spinoza after Spinoza left the Jewish community and even had letters sent and received for the philosopher to and from third parties. Spinoza and Serrarius maintained their relationship until Serrarius' death in 1669. By the beginning of the 1660s, Spinoza's name became more widely known. Henry Oldenburg paid him visits and became a correspondent with Spinoza for the rest of his life. In 1676, Leibniz came to the Hague to discuss the "Ethics", Spinoza's principal philosophical work which he had completed earlier that year.