"Primarily found within the nations of Germanic Europe and the neighbouring areas which they have influenced, its origins remain unknown, although it has been speculated that it originally had some importance in the Germanic paganism[4] of Iron Age and early Medieval cultures, and that the tradition survived Christianisation, albeit losing any original meaning that it had. It has been a recorded practice in many parts of Europe throughout the Medieval and Early Modern periods, although became less popular in the 18th and 19th centuries. Today, the tradition is still observed in some parts of Europe and among European communities in North America.[5]"
cen.wikipedia.org/wiki/Ceremonial_pole

BTW the Germanic Saxons seem an amalgamation of various tribes which caused the Romans such problems in 9AD.

PS en.wikipedia.org/wiki/Maypole

Samuel Pepys wrote in his diary what he saw in the Hague on 14 May 1660: "may-poles, which we saw there standing at every great man’s door, of different greatness according to the quality of the person".