Earliest settlement proto-urban cluster There has been human settlement in the area for more than 40,000 years; archaeological investigations have placed human presence here back to the
Mesolithic Period, when the first peoples began to concentrate in the areas around Alcácer. This period was characterized by exploitation of the ecosystem in the Sado Estuary, when the river extended to São Romão, involving fishing, scavenging for shellfish, hunting and foraging in the local forests. The primitive tools, made from
chert, were adapted from the techniques of the late
Paleolithic era. By the late Mesolithic period, people had concentrated in the area of Comporta and
Torrão, later establishing primitive defensive protection to support their communities. These principal settlements were abandoned by the
Copper Age, but repopulated during the
Iron Age, as was the case of Alcácer. Mediterranean trade, pioneered by the
Phoenicians, introduced commercial colonies in Abul and Alcácer (then referred to as
Bevipo or
Keition), where a written alphabet and currency allowed commerce to flourish.
Roman Era After the
Third Punic War, with the fall of
Carthage, Alcácer was annexed to the
Roman Empire (around 1st-2nd century B.C.). The municipality of present Alcácer became known as
Urbs Imperatoria Salacia in honor of the sea god
Neptune's wife, nymph
Salacia, for its importance in the Iberian
salt trade and the number of
routes that crossed the area. In the third century the port of Salacia fell into disuse thanks to the emergence of
Olisipo (
Lisbon). With the rise of
Gaul, most of
Hispania became a vassal state of the larger empire. Returning to the Imperial fold with the 296AD reorganization of Roman territories by
Diocletian (in order to subvert the
Military Anarchy that existed at the time), Salatia's role was transformed. Circa 300? it was the seat of a Diocese of Salácia (Portuguese) / Salacien(sis) (Latin) / Salarien(sis) (Latin), which was however suppressed around 350. In the following centuries, Salatia became a poor distant colony of the much larger centers of
Setúbal or
Lisbon. The only exception was Torrão, which continued to prosper. Until 711, when the region was annexed by the
Umayyad Caliphate of
Damascus, the population of the hilltop areas of Salatia left in favor of the low lands along the river.
Al-Andalus The
Ummayad rule on the
Iberian Peninsula, in the reign of Abu-l-Khattar (743-745) over the region of Beja, which included Alcácer, was noted for the recruitment of troops, and for the rising power of Yemeni clans in southern Portugal. The entire region was later administered by Egyptian Arab troops, that selected Beja as their regional seat. Until 844, Alcácer functioned as center for the collection of taxes in the lower Sado valley: collected primarily from the Christians who chose to remain in the valley. The first Viking raids in this year forced a political reorganization, and Alcácer became an important outpost of
Al-Andalus. After an internal victory over
Muwallad rebels in 888, the city was offered as reward to the
Banu Dānis clan, and its
keep was renamed (قصر أبي دانس; ), commonly known simply as (). The village of was the base for a large fleet and arsenal that was used during the Christian-Moorish
Reconquista. In 997 a Moorish fleet transported troops from Alcácer to
Porto, to support
Al-Mansur Ibn Abi Aamir, that culminated in the destruction of the sanctuary of
Santiago de Compostela. It was then capital of the Province, which by the 12th Century was a center of merchant traffic, supported by the opulent tastes of Évora.
Muhammad al-Idrisi noted that forestry, and in particular pine tree harvesting, was important during this period, as was cattle raising and major agricultural cultivation. However, the Norwegians then sailed on to the
Holy Land and the town - with whatever inhabitants survived - remained Muslim. During the
Fifth Crusade, when
Afonso II of Portugal had a truce with the
Almohads, Sueiro Bishops of
Lisbon and
Évora joined the
Cistercian abbot of
Alcobaça, the commander of
Palmela, the
Templars, the
Hospitallers, and
magnates, in an attempt to persuade the crusaders to attack the
Moors in Alcácer do Sal. The city of Alcácer had been lost since 1191 in the aftermath of the Third Crusade campaigns of Alvor and Silves. The keep in Alcácer was conquered for the first time by the Portuguese in 1160. In 1191, it returned to
Amazigh hands under the direction of
Yaqub al-Mansur, who transformed it into the military garrison of
Garb al-Andalus. According to
De itinere Frisonum the Frisian
Crusaders refused to help on account of Innocent III prohibition to Bishop Souiro, and departed for the
Holy Land, even after being provided food, expenses, and rousing oratories about the Almohads' annual demands for 100 Christians in tribute. Meanwhile, ships under the command of
William I of Holland and Count George of Wied arrived in Alcácer do Sal on 2 August 1217. They were joined by the Portuguese sent to lay siege to the castle. Muslim governors in
Seville,
Córdoba,
Jaén and
Badajoz attempted to relieve the garrison but their reinforcements were defeated on 11 September. The castle surrendered on 18 October 1217, with additional Christian troops provided by Pedro Alvítiz from Castile. Once the castle was taken, many of the northern Crusaders requested
Pope Honorius III allow them to remain for a year
"for the liberation of Hispania" and
"the extirpation of the perfidious cult of the pagans". In 1218, Alcacer do Sal received its
foral from King
Afonso II, and handed over to the Knights of Santiago, who made it their headquarters during their advance into the
Alentejo and
Algarve. == Geography ==