HISTORY. The Kingdom of Tonga attained unity under Taufa’ahau Tupou (George I) who became ruler of his native Ha’apai in 1820, of Vava’u in 1833 and of Tongatapu in 1845. By 1860 the Kingdom had become converted to Christianity (George himself having been baptized in 1831). In 1862 the King granted freedom to the people from arbitrary rule of minor chiefs and gave them the right to the allocation of land for their own needs. These institutional changes, together with the establishment of a parliament of chiefs, paved the way towards the democratic constitution under which the Kingdom is now governed, and provided a background of stability against which Tonga was able to develop her agricultural economy.