Disheartened by their successive failures to secure a desirable part of the country wherein they might settle, the Boers again "trekked" northward over the Dragon Mountain. There they occupied the territory south of the Vaal River which had a short time previously been deserted by Potgieter and his party, who had journeyed northward with the intention of joining the Portuguese colony at Delagoa Bay, on the Indian Ocean. These pilgrims were attacked by the deadly fever of the Portuguese country, and after remaining a short time in that region moved again and settled in different localities in the northern part of the territory now included in the South African Republic. Moselekatse and his Matabele warriors having been driven out of the country by the other "trekking" parties, the extensive region north of the Vaal River was then in undisputed possession of the Boers. The farmers who left Cape Colony in 1835 and 1836 in different parties and after various vicissitudes settled across the Vaal were less than sixteen thousand in number, and were scattered over a large area of territory. The nature of the country and the enmity of the leaders of the parties prevented a close union among them, although a legislative assembly, called a "Volksraad," was established after much disorder. The four principal "trekking" parties had sought four of the most fertile spots in the newly discovered territory, and established the villages of Utrecht, Lydenburg, Potchefstrom, and Zoutpansberg. When the Volksraad was found to be inadequate to meet the requirements of the situation these villages were transformed into republics, each with a government independent of the others. The government of the limited areas of land occupied by the four republics was fairly successful, but the surrounding territory became a practical no-man’s-land, where roamed the worst criminals of the country and hundreds of detached bands of marauding natives. The Boers imposed a labour tax upon all the natives who lived in the territory claimed by the four republics, and for a period of ten years the taxes were paid without a murmur. About that time, however, the native tribes had recovered from the great losses inflicted upon them by the emigrant farmers, and they were numerous enough to make an armed resistance to the demands of the governments. White women and children were massacred and property was destroyed at every opportunity. For purposes of self-preservation the four republics decided to unite the governments under one head, and, after many disputes and disorders, succeeded, in May, 1864, in forming a single republic, with Marthinus Wessel Pretorius as President, and Paul Kruger as commandant-general of the army.