To my mind the Atlanteans were almost certainly the progenitors of the Hellenes. Hellen was supposedly the son of Deucalion (or Zeus in another account) and the grandson of the Titan, Prometheus. Atlantis is heavily associated with the sons of Poseidon though, the first king alleged to be his son Atlas (not the Titan Atlas). It is for whom Atlantis is named. What should be remembered at this point is Atlantis is merely the capital city of the Aegean landmass (see Maps).
The geography of the Aegean would have been vastly different at the end of the last ice age. Homer possibly makes a vague reference to Atlantis but there is much conjecture and very little evidence to support the theory. Plato says 9000 years before the time of Solon (600 BC) but although this would put it to the time of the end of the ice age (9600 BC), there is still debate over the numeric anomalies not shared by others in antiquity.
The anomaly is as discussed most likely due to differences between the Egyptian and ancient Greeks, Plato travelled to Egypt and was known to employ an Egyptian scribe. Maybe many of Plato's works were simply what he dictated. It would explain why others didn't have the same numeric problem. Taking the demise of Atlantis with the amended Plato figure of 900 we get to the magical 1500 BC figure again. Calling the Atlanteans or their ancestors the Olympians and Titans, 'alien visitors' might well explain a lot of things, but I cannot get my head round how such an advanced race, had founded their capital city on a ticking time bomb. Surely they would understand plate tectonics.
Another possibility is a more advanced tribe migrating south from the extensive ice sheet. Perhaps they took up refuge on the Aegean landmass which would have been almost inaccessible. To the east and west of 'Aegea' would likely have been marsh and salt lakes, inaccessible by sea or land. Only as sea levels rose could it be circumnavigated. A closed border policy would be easy to enforce and a civilisation evolving in seclusion might well advance at a faster rate. It could just be there is no mystery at all. Why rationalise the incredible when the simple answer makes perfect sense.
The remnants of the ancient city of Atlantis?
Excavations on Santorini (Thera) have revealed frescos and scenes reminiscent of those described by Plato. As discussed though, it would be folly to take too much notice of Plato or even Solon, the source of the story, as both were heavily influenced by personal agenda as well as the politics of the time. The differences between the Hellenes pretty much reflect those detailed by Plato / Solon in accounts of Atlantis.
When considering plausibility, It is reasonable to assume Atlantis was inhabited by a relatively advanced race from the end of the ice age. First accounts give a date of 2112 BC when the ruler of the local Pelasgians was Evenor. This gives a solid basis for dating the Atlantean / Hellene / Olympian colonisation. Evenor's daughter Cleito, was supposed to have borne Poseidon's children, including Atlas, the first king of the Dorian region after the Olympians left.
Perhaps Evenor was killed in the cataclysm that caused the Olympians to evacuate. Could this even be the basis for the Titanomachy myth. It would have been when Atlas was adult and would give a date somewhere between 2090-2050. This is very close to the date attributed to the first Attican settlement by Hellenes. We can only speculate what happened and so will not place too much emphasis on the dates just yet (in Part IV my personal hypothesis is detailed in story-form).
Plato's account suggests the Atlanteans were war-like, yet I feel they were what they had to be. I believe they valued trade over conquering other nations. Circumstances caused the migrations which at first were welcome due to what they brought to the table. However, land was being lost to the sea and coastal areas were constantly under threat from tsunamis. The once welcoming nations were struggling for resources without a further drain from the influx of Atlanteans, however smart they were.
As sea-levels rose the Atlanteans - or more specifically the Dorians - used their nous to become a major sea power, dominating trade as the eastern Mediterranean became more accessible. They may have had the capabilities to wage war but I doubt they did so before 1650 BC. One theory I have is the migrations would likely occur after a natural disaster. A tsunami might well clear a coastal area, wiping out villages and killing the local people. The Atlanteans would seem to sweep all before them.
The demise of Atlantis I always thought to be an eruption on Santorini due to early research giving an eruption on that date. This has since been put aside as a possible date for the Santorini eruption which is given as 1650 BC. There is however evidence on Crete of earthquake and tsunami damage dating to 1450 BC and it suggests to me that 1650 BC was the date of the eruption but an earthquake in 1450 BC caused the whole central caldera to collapse, not just overnight, in minutes.