Complicating matters were commercial disputes. The activities of English sailors, begun by Sir John Hawkins in 1562, gained the tacit support of Elizabeth, even though the Spanish government complained that Hawkins's trade with their colonies in the West Indies constituted smuggling. In September 1568, a slaving expedition led by Hawkins and Sir Francis Drake was surprised by the Spanish, and several ships were captured or sunk at the Battle of San Juan de Ulúa near Veracruz in New Spain. This engagement soured Anglo-Spanish relations and in the following year the English detained several treasure ships sent by the Spanish to supply their army in the Netherlands. Drake and Hawkins intensified their privateering as a way to break the Spanish monopoly on Atlantic trade. Francis Drake went on a privateering voyage where he eventually circumnavigated the globe between 1577 and 1580. Spanish colonial ports were plundered and a number of ships were captured including the treasure galleon "Nuestra Señora de la Concepción". When news of his exploits reached Europe, Elizabeth's relations with Philip continued to deteriorate.