1790-1838. Missionary to South India. From a Prussian officer's family, he attended Jänicke's* mission school in Berlin and went to India under the Church Missionary Society in 1814. After serving briefly in Madras, he moved to Tinnevelly where he proved to be a competent scholar, effective teacher-catechist, and outstanding organizer. He prepared a Tamil grammar and NT, and introduced a system linking the village church and school where the schoolmaster had responsibility for worship and religious instruction. The work was self-supporting and self-propagating, and so many lower-class people were converted that the British authorities feared social unrest. Having never received Anglican orders, Rhenius ordained Indian ministers himself, but the CMS forbade the practice. In 1835 he challenged this and was discharged. Because many Tinnevelly congregations remained loyal to him, he formed a separate church, but the schism was healed after his death.