Montevideo, the capital of Uruguay, is about to celebrate the 300 years of its foundation in 1724. The arrival of a slave ship to the harbor of Montevideo in December 1723 accelerated the Spaniards’ establishment of this city, located in lands and waterways claimed by the Spanish and the Portuguese monarchies in the Atlantic littoral of South America.
Starting in 1713, two decades before the founding of Montevideo, the London-based South Sea Company began to bring enslaved Africans to the Spanish colonies. The British captains carrying captives to Buenos Aires, in today’s Argentina, entered from the Atlantic to the northern bank of Río de la Plata (River of Silver), usually anchoring in the bay of Montevideo to embark water and food. The lands surrounding the harbor were inhabited only by indigenous people with frequent contact and trade with the Spaniards and Portuguese. As these were foreign waters to the British, the captains sent a boat from Montevideo to cross the river to Buenos Aires, on the southern bank, to request a ship’s pilot to come from Buenos Aires to help the British vessel cross the river, avoiding dangerous sandbanks –the most famous named the “English sandbank.” The Rio de la Plata, considered the world's widest river, is technically an estuary.
These crossings of the South Sea Company’s ships also occurred in the opposite direction. After the British mariners disembarked the African captives in Buenos Aires, they loaded mostly silver and cattle hides to take them to Spain or England. For sailing out of Buenos Aires, these vessels again needed the port pilot's help to cross to Montevideo. While the pilot returned to Buenos Aires, these ships continued to the Atlantic. Through this coming and going of slave ships across the river, the Spanish in Buenos Aires learned of the Portuguese founding of Montevideo.
The South Sea Company’s ship King William sailed from London in July 1722, captained by William Hamilton and with a large crew of 60 mariners. In September, Hamilton arrived at Loango (today’s Republic of the Congo) and began loading more than 600 enslaved men, women, and children. The King William arrived in Buenos Aires in March 1723 with 557 African survivors. Mortality continued after the Atlantic crossing, as at least 19 died in the city. For most of the 357 men and 198 women still alive, Buenos Aires was not the end. Of the 835 Africans from the King William and another vessel arriving later that year, 230 were further removed from Buenos Aires to Chile, probably heading to Lima in Peru, and 425 to Potosí, in today’s Bolivia, continuing their tortuous passages into the highlands and the Pacific littoral of South America.
On November 5, 1723, Hamilton paid the royal duties after embarking cattle hides from Buenos Aires and yerba from Paraguay to take them to England. He surely carried smuggled silver. Then, the King William departed from Buenos Aires with the port’s pilot, Pedro Gonardo, to Montevideo’s harbor. Gonardo quickly returned to Buenos Aires on December 1st with news for Governor Bruno Mauricio de Zavala about a Portuguese warship and three other transports anchored in Montevideo. On the peninsula enclosing the harbor, now the Old City or Ciudad Vieja, 300 men had raised tents and were building a fort, claiming the site for the Portuguese crown.
Upon hearing this news, Zavala speeded the arming of ships and troops to evict the Portuguese and establish Spanish Montevideo. However, there were very few vessels then in Buenos Aires because trade was restricted to registered ships with special permits from Spain. The arrival of these vessels was infrequent since none had reached Buenos Aires between 1721 and 1727, which explains the intense smuggling with the Portuguese.
The Governor of Buenos Aires prepared four ships: the two warships defending the city, a smaller vessel, and a slave ship from the South Sea Company (not without resistance from the representatives of this company). This ship was the Saint Quintin, which had arrived in Buenos Aires in July 1723 from Cabinda (in Angola) with 299 captives.
Zavala gathered about 500 men to evict the Portuguese, who left Montevideo days before this contingent's departure due to the news that had reached the latter about the outfitting of this force. On January 20, 1724, the four ships with men and supplies left Buenos Aires to establish a Spanish military outpost in Montevideo. Then, one thousand Tape indigenous people, allied with the Spanish, arrived and began the construction of artillery batteries in the corners of the peninsula and a fort in its center. The Spanish permanent garrison was slightly more than one hundred men, so the Tapes were armed for their defense, too. The slave ship Saint Quintin left Montevideo five months after transporting these troops, setting sail for London in late June 1724.
This story reveals the slave trade’s shaping of the founding of Montevideo. Also, it shows the importance of this traffic to the Atlantic links of this region since the South Sea Company’s ships were the only ones arriving in Buenos Aires in 1723. This explains why Zavala had to employ one of these vessels to transfer the contingent claiming Montevideo for Spain, starting the entanglements of slaving connecting Montevideo with Africa and Brazil for over a century.