The Moroccan system was visited, and in some instances crossed, by various European travellers carried into slavery by the Salli rovers, and was traversed by Rene Caille in 1828 on his journey home from Timbuktu, but the first detailed exploration was made by Gerhard Rohlfs in 1861-1862.
After the departure of the Romans the walls became ruinous or were partly pulled down, perhaps by sea rovers from the north.
The necessity of seeking protection from the sea-rovers and pirates who infested these waters during the whole period of Hanseatic supremacy, the legal customs, substantially alike in the towns of North Germany, which governed the groups of traders in the outlying trading posts, the establishment of common factories, or "counters"(Komtors) at these points, with aldermen to administer justice and to secure trading privileges for the community of German merchants - such were some of the unifying influences which preceded the gradual formation of the League.
BARBAROSSA ("Redbeard"), the name given by the Christians to a family of Turkish admirals and sea rovers of the 16th century, - Arouj and Khizr (alias Khair-ed-Din) and Hassan the son of Khair-ed-Din.
The island of Columba was occasionally plundered by English and other rovers, but in the 16th century it became the property of Sir James Stuart, whose grandson became 2nd earl of Murray by virtue of his marriage to the elder daughter of the 1st earl.