The Siege of Colonia del Sacramento was a successful siege in 1704 by Spanish forces of the Portuguese

Kingdom of Portugal

The Kingdom of Portugal was Portugal's general designation under the monarchy. The kingdom was located in the west of the Iberian Peninsula, Europe and existed from 1139 to 1910...

 colonial town of Colonia del Sacramento

Colonia del Sacramento

Colonia del Sacramento is a city in southwestern Uruguay, by the Río de la Plata, facing Buenos Aires, Argentina. It is the oldest town in Uruguay and capital of the departamento of Colonia. It has a population of around 22,000.It is renowned for its historic quarter, a World Heritage Site...

, opposite Buenos Aires

Buenos Aires

Buenos Aires is the capital and largest city of Argentina, and the second-largest metropolitan area in South America, after São Paulo. It is located on the western shore of the estuary of the Río de la Plata, on the southeastern coast of the South American continent...

 and now in the nation of Uruguay

Uruguay

Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...

. Four thousand natives and 650 Spaniards, led by the governor of Buenos Aires, Don Alonso Juan de Valdes e Inclán, and Baltasar García Ros, besieged the city beginning late in 1704. One week after a frontal assault failed, in early February 1705, the Portuguese abandoned Colonia del Sacramento.