According to "Neanderthals: Facts About Our Extinct Human Relatives" (Szalay, 2013), Neanderthals dominated Europe during the last Ice Age, but may have died out before the arrival of Homo Sapiens (according to research detailed in "Radiocarbon dating casts doubt on the late chronology of the Middle to Upper Palaeolithic transition in southern Iberia" (Wood et al. 2012).
There are a number of theories floating around in the literature - everything from inability to adapt to climate change to dietary deficiencies.
What does the latest research suggest as the cause of the Neanderthal extinction?
(refereed papers would be appreciated)