The Brazilians complain to the Argentine government on account of the decided protection it had given to the Oriental Revolution, and a war ensues between both nations that obliges the Argentines to send an auxiliary army to this territory. The struggle went on, being a series of victories for the united republican arms: the Imperial power was defeated, the last encounter, that put that memorable campaign to an end, taking place in Bacacay. Negotiations of peace were undertaken, and on the 27th of August, 1828, the preliminary treaty was signed, by which the Oriental Province of Uruguay was declared sovereign and independent. A provisional government was appointed and, after the country had recovered peace and quiet, a constituent and legislative Assembly was elected which compiled and published the Constitution that nowadays is still ruling, and that was solemnly sworn amid the greatest popular joy on the 18th of July, 1830. It was at this period that a man rose into note in the Argentine Confederation who was destined to exercise an overshadowing and pernicious influence on both sides of the River Plate. In 1829 Don Juan Manuel Rosas became Governor of Buenos Ayres. Possessed of great capacity he maintained tranquility in his native province and extended his sway over the neighboring states of the Confederation; but his system of government was despotic, and his rule was for some years one of sanguinary terror. His intervention in the intestine quarrels of the Republic of Uruguay, and his attempt to close the River Parana to foreign vessels, led him into hostilities with England and France, whose joint naval squadrons protected Montevideo from his attacks by sea, whilst his troops and their Oriental allies, under General Oribe, besieged the city. The siege of Montevideo by the _Blancos_ or _Whites_, as the Oriental partizans of Oribe were called, continued for nine years, and for that period, from 1843 to 1851, the history of the Republic of Uruguay is the history of the defence of Montevideo. The defence concluded with a treaty of peace on the 8th of October, 1851, in which it was declared that there were neither conquered or conquerors.