The Rio Arade was long an important route into the interior for the Phoenicians, Greeks and Carthaginians, who wanted the copper and iron action in the southwest of the country. With the Moorish invasion from the 8th century, the town gained prominence due to its strategic hilltop, riverside site. From the mid-11th to the mid-13th centuries, Shelb (or Xelb), as it was then known, rivalled Lisbon in prosperity and influence: according to the 12th-century Arab geographer Idrisi, it had a population of 30, 000, a port and shipyards, and ‘attractive buildings and well-furnished bazaars’.
The town’s downfall began in June 1189, when Dom Sancho I laid siege to it, supported by a horde of (mostly English) hooligan crusaders who had been persuaded (with the promise of loot) to pause in their journey to Jerusalem and give Sancho a hand. The Moors holed up inside their impregnable castle with their huge cisterns, but after three hot months of harassment they ran out of water and were forced to surrender. Sancho was all for mercy and honour, but the crusaders wanted the plunder they were promised, and stripped the Moors of their possessions (including the clothes on their backs) as they left, tortured those remaining and wrecked the town.
Two years later the Moors recaptured the town. It wasn’t until 1249 that Christians gained control once and for all. But by then Silves was a shadow of its former self. The silting up of the river – which caused disease and stymied maritime trade – coupled with the growing importance of the Algarvian ports hastened the town’s decline. Devastation in the 1755 earthquake seemed to seal its fate. But in the 19th-century local cork and dried-fruit industries revitalised Silves, hence the grand bourgeois architecture around town. Today tourism and agriculture are the town’s lifeblood.