Since Professor Sp. Marinatos linked the eruption of Thera with the destruction of Cretan sites, difficulties have been met in reconciling the dates of the two incidents which, based on pottery, were c. 1520 BC and 1450 BC, respectively, giving a “time gap” of 70 years. None of the mechanisms proposed for the Cretan site destructions-tsunamis, ash fallout, earthquakes, civil disturbances or invasion can be reconciled with the magnitude of the simultaneous site destructions. Therefore, an alternative theory is proposed that the Cretan holocaust was caused by “nuées ardentes” emanating from Thera. It is postulated that these were released through a “split” in the cone wall, of limited area, generating a high velocity jet of tephra fluidized in a red hot gas stream. Such a jet is immensely destructive and lethal, causing death by pulmonary oedema. The shape (like a blowtorch) and course of the ash fallout, as measured by deep sea cores, shows that these nuées ardentes passed over the eastern part of Crete, causing severe destruction and depopulation. The geological record confirms that tephra deposits from such Peléan eruptions have travelled for 160km, or more, and that normally the main eruption is preceded by a preliminary one of lesser intensity, with a time gap ranging from 51 to 203 years. Settlements on or at the base of the volcano would have been abandoned at the time of the preliminary eruption/earthquakes ( c. 1520 BC). A time gap of 70 years would be reasonable, fitting with the Cretan catastrophe around 1450 BC. In the meantime, reoccupation had commenced, but was terminated by the final eruption. Apparently, Knossos on the periphery of the blast was severely damaged by fire (possibly again in LM II) and rebuilt, being finally destroyed in late LM IIIB. During this time span some “blurring” of pottery dating may be attributed to recovery and use of pottery “heirlooms”. The nuée ardente theory explains the simultaneous destruction of sites by fire and blast, the Cretan depopulation, as well as the time gap. In general 14C results confirm the dates proposed. So far tephra deposits have not been identified on Crete itself, but grains of it have been found at Pyrgos. It is suggested that cores from lake bottoms should be examined for the area, and that Cretan soil samples should be checked for tephra particles by employing the flotation technique, used in mining, for separating them.