For a long time, Britain had beers associated with Christmas that weren’t explicitly billed as Christmas beers.
If Frank Baillie’s 1973 Beer Drinker’s Companion is anything to go by, there were certainly winter ales released in November or December in time for Christmas, but they didn’t feature Father Christmas on the pump clips or labels; they weren’t called things like Rudolf’s Throbbing Conk; and they weren’t dosed with cinnamon and nutmeg. As far as we can see, Shepherd Neame’s bottled Christmas Ale was the only one with Christmas is in its name at that time.*
Based on looking through old copies of the Campaign for Real Ale’s Good Beer Guide (thanks again, Ed!) it looks as if the idea of marketing ‘winter warmers’ as Christmas beers really took off in the increasingly competitive real ale scene of the 1980s. The 1987 GBG (published in 1986) lists around ten beers that we would classify as definitely Christmas seasonals, such as Mauldon Christmas Reserve, Wood’s Christmas Cracker and the Bridgewater Arms’s Old Santa.