The age of subclade “R-L2” is estimated to be 3,500-4,500 years. (Source: FTDNA)
Origins: Alpine Celt > Flemish Celt > Flemish Norman > Scoto Norman
originated around 2,500 BCE, then proliferated within Alpine Celt cultures of Hallstatt (1200 BCE) and the La Tène.
Then, around 500 BCE, the La Tène culture began to spread from the Alps to most of Western Europe, which was when the Haplogroup R1b migrated from the La Tène culture to the Flemish culture of Flanders, bringing with them the Celtic culture.