Let's face it, the ancestors were head-hunters.
According to the Roman geographer Strabo, writing in the first century BCE
The Gauls practice a custom common to many northern tribes. In battle, they hang the heads of their slain enemies around the necks of their horses, then at home they hang them on pegs in their houses.
The practice persisted for a surprisingly long time. While in Scotland, I paid a visit to the Well of the Seven Heads, where in 1663 a McDonald war-party stopped to tidy up the severed heads of seven clan rivals before presenting them to their chieftain.
Of course, the McDonald Himself probably didn't hang them around the Great Hall afterward.
What, I ask myself, would it be like to live in a home with severed heads hanging from the walls? While, say, you were eating dinner?
Surely they must have cured them in some way? Surely the stink would have been prohibitive otherwise? ("Oh Luvernios, not another one!") Of course, the old Celtic roundhouses lacked louvers—smoke-holes—over their central fires; smoke just percolated out through the thatch. It would have made for a smokey house-place, but also have kept down insects, and made an ideal environment for preserving meats. I suppose, with time, the heads would have dried and smoked along with the sausage and hams.
I look up into the eyes of the Green Man hanging above the computer. Like many pagans, I have many in my home: maybe 30 or so. (Every time I try counting them, the total is always different.)
Green Men we call them, but let's face it: they're Green Heads, mostly. In my own way, I suppose, I'm as avid a collector of heads as the doughtiest Celtic warrior.