I was intrigued by the Vikings in Morocco thing so I should say thank you to the uploader of that ATL.
I had suggested that a Viking Canary islands would be better but no one seemed to give a damn so I will.
Circa 900 AD and the Vikings have colonized Iceland and the Faroes and within a century they reach Greenland and North America.
The Vikings were familiar with the Arabs and they did clash with them occasionally.
Just suppose a small group of ships make their way down the Moroccan coast looking for plunder or an anchorage. One day they are blown off course and find the Canary Islands. The Arabs were there by 999 at the latest and the Romans had been there too.
They land and get provisions and kill a few seals. They see some primitive natives who just watch them in disbelief.
They note the low technology of the natives and figure out the way back home. Later they decide to return to check out the place a little more and like what they see so they establish themselves around an anchorage.
The local Guanche chief meets them to find out who they are. The Vikings show themselves to be too tough to be dealt with easily so the chief turns a blind eye to their presence. A big mistake because a year later they return with a force of 200 heavily armed Vikings who destroy his tribe and enslave the women. The Canary islands are divided into many petty Guanche kingdoms so there is little organized resisitance.
These are picked off one by one during the next 50 years. The Initial viking colonisation is small, about 800 warriors settle permanently with about 500 women and children and many intermix with the locals giving a Viking mixed blood population of about 5000 by the year 960. They set up their own informal parliament similar to Iceland.
Agricultural techniques acquired from the Arabs and the Normans transform the local economy from the early 1000's and the population begins to increase significantly. A few isolated groups of Norwegians continue to land so the Viking heritage doesn't disappear. This leads to the settlement of other islands in The Canary's and more local wars with the tribes. Usually the vikings win but not always. The Guanches learn a few tricks from the Vikings.
Another big change occurs after 1066. The Norman conquest of England and its brutal aftermath leads to an exodus of Anglo Saxons and Norse to all parts of Europe even to Constantinople. However one group has heard of a warm place in the south sea where no feudal lords will try to control them and where settlers especially ones with military and artistic skills are always welcome.
They are given a crude map in Northern Spain and they set sail in a fleet of 30 ships carrying 1200 people including family groups and some nobleman. The Vikings are shocked to see such a large group suddenly arrive but they welcome them as kindred spirits. They wisely scatter them throughout the island group. They help to offset the fear that some Vikings had of their people being absorbed into the local population. Over next generation other Norse settlers from England follow perhaps as many as another 4000.
By 1100 the Viking/mixed blood population is 28,000. They have a few small towns and are trading with Spain and North Africa. The language problem is solved by the adoption of the Norse language of Northern England since they are now seen as the most influential group in the new society. There is some discrimmination against darker skinned Vikings based on fear of being overwhelmed.
Their ships have evolved over the last 100 years and are better adapted for larger cargoes and more passengers than the old Longships, though some of these are still built. They begin to explore the African coast and have chartered what is now the Mauretanian coast.
In 1075 Ranulf the Brown Nose is whale hunting when a storm blows him off course. For days they use the stars to figure out their position in a desperate attempt to get home. Suddenly he sees a mountain that seems to rise out of the sea. He has discovered Madeira.
By 1150 a trickle of Norse settlers continue to arrive from England and Ireland. There are also some Iberians fleeing the wars between the Christians and the Moors though they are less welcome if they don't have fair hair or blue eyes. The non indigenous population is now 52,000 and they are served by about 10,000 guanche slaves. There are also 2,000 settlers on Madeira. There is now a bishop and a rudimentary cathedral.
The islands are now producing wine, whale oil, fish and fruits. Most of this is for domsestic consumption but more and more is for export. They are also developing a carrying trade along the Moroccan and Iberian coasts. Coins are now being minted and they are getting skilled at map making.
By 1160 they reach the Gambia river and take the first consignment of Ivory. In 1165 they set up their first 'factory'. Because they are seen as small no one considers them a threat also because many have mixed Norse/guanche blood they are better suited to the climate than later Europeans.
By 1200 the wealth is starting to show. The Cathedral is being rebuilt and expensive religious relics arrive. The Anglo Norman invasion of Ireland had brought another wave of settlers so the Population had swollen to 90,000 plus about 10,000 Guanche and some Castillian slaves. The islands are now as wealthy as one of the smaller Italian city states. Corsairs from North Africa now launch the odd raid so the islands develop a small navy of ships that are better designed than the Arabs.
In 1209 they establish an outpost in what is now Ghana and they collect their first shipment of gold. A year later they seize a Moroccan trading vessel in the area carrying gold and ivory. It is small scale at first but the 'Vikings' start taking to piracy in addition to their trading activites. By 1215 they have charted The Azores and the Islands are opened up by the now powerful merchant class to colonisation. One of the first groups to arrive are some Frankish and Flemish refugees from the Holy Land. They are offered land in the Azores in exchange for technology, religious relics and precious gems. They must also promise to accept the sovereignty of the home parliament on Gran Canaria. Over 2000 settlers arrive.
With government now more complicated the vikings elect a leader who governs through the parliament. The Parliament is controlled by the old families but now the Merchants are rich too and they muscle in and demand new laws that protect wealth and regulate the economy.
The Norse language has evolved by adding Arabic and Castillian loan words and idioms. A literature is starting to emerge and schools are opening. Latin never got the power it did in Europe and the church was in practice independent of Rome.
In 1222 a ship mostly crewed by Holy Land Franks from the Azores sets off west. The captain has a scroll written in arabic. The original author was a Greek guy called Plato and one word in that scroll had seared its way into the captain's brain. The word was Atlantis. He had spent his whole life looking for it.
In October 1222 his feet were walking on an island we now know in our OTL as Puerto Rico.
I have stopped at 1230. We have a population of about 100,000 plus 15,000 slaves. A kind of Norse style parliament evolving into something more modern. We have an ocean going fleet covering three island groups with a small establishment growing on the African coast.
We also have a landing in the Carribean 270 years before Columbus by a man looking for Atlantis but owing allegiance to the Viking Canary state.
Is this stupid? Is my Viking kingdom going to be destroyed by other