The history of man's inhabitance in Sligo can be traced back to as early as 5000BC. Approximately 5km south of Sligo airport, stands Europe's largest collection of Megalithic tombs.
Since ancient times, the Connaught County has been of utmost strategic and logistical importance, as all traffic on the coastal route between North and South had to ford the river here. A fortress which guarded this ford was plundered by Norse pirates in and around 807 AD. As a result of its location, the county was often suffered attacks from the heads of clans and the English.
In 1558, ships of the Spanish Armada were destroyed during a storm off Streedagh Beach. A number of Spaniards managed to evade the English and returned to Spain.
Sligo was granted to Maurice Fitzgerald after the Norman invasion of Connaught in 1235, and he effectively founded Sligo town by building a castle there in 1245 and making it his residence. Further settlers were brought into the county at various periods, including weavers from the north of Ireland brought in by Lord Shelbourne in 1749.
Sligo also played a significant role in the war of Rebellion in 1798, when the Franco-Irish army had succeeded in pushing back the English. A statue to the memory of Bartholemew Teeling was erected in the town of Collooney for it's role in this battle.
Sligo reached international renown in the beginning of the 20th Century, when WB Yeats wrote about the magical rural beauty of the County in the lines of his early poems.