Spain and Portugal in Europe, Brazil and the Argentine in South America, were always inharmonious neighbors, even when allied, which was only occasionally for they were more frequently at war. Carlota, a sister of Ferdinand VII, married the Portuguese Prince Regent who lived at Rio, and planned to rule both Brazil and the River Plate. Brazil became an independent kingdom on May 13, 1816, and in the same year Montevideo separated itself from Buenos Aires, with which it had been connected since Alvear and Brown took it from the Spanish in 1814. Brazil captured Montevideo in 1817 and held it for ten years, thus bringing a new danger to the doors of Buenos Aires. After the Tucumán Congress, San Martín came up from Mendoza and met Pueyrredón on July 15, 1816, at Córdoba. As in all the San Martín conferences this one was surrounded by mystery, but it is known that among other things Pueyrredón approved of San Martín's plans to attack the Spaniards in Chile, and promised his aid. San Martín returned to Mendoza, and completed his preparations. He brought back word that the Supreme Director intended to liberate all slaves, and suggested that owners anticipate the act of emancipation and turn their slaves into the army. By this means he added 710 colored troops to his infantry, that being the branch of service he desired to strengthen. He found a practical chemist and made powder locally. He discovered a young priest, Fray Beltrán, with a turn for mechanics, and made him chief of ordnance. Beltrán not only made rifles and cast cannon, but invented successful devices for transporting heavy and cumbrous articles over the rugged Andes. Shoe-makers and harness-makers and clothes-makers, and the makers of all the rest of the multitudinous articles required by an army, were found or improvised. San Martín needed mounts for the cavalry, and he induced local ranchmen to sell him horses at six "pesos" each, payable in script acceptable at the local Custom House. He obtained 900 head. By the middle of January, 1817, he was ready to start. To divert attention and confuse the Spaniards, four expeditions simultaneously crossed the mountains. One left San Juan and took the road for Coquimbo; another left La Rioja with Copiapó as destination; a third went through the southern pass which lead to Talca; while the main force, in two divisions, took the nearer routes. Las Heras, with the artillery, went over the Uspallata trail, through the divide where the Christ now stands; while San Martín with the bulk of the army, travelled the Los Patos road, some forty miles to the north. The two columns were to meet at Chacabuco on the Chilean side. The entire undertaking was perfectly planned and admirably executed.