I'm going to give some context to this.
So, before 2011, Christmas ads weren't this eagerly anticipated. There wouldn't be an individual, lavish advert but more several adverts with the same theme. The likes of John Lewis did do them, but they didn't really catch the public imagination.
Then the JL ad for 2011 came out and, coupled with M&S' X-Factor ad for that year, the battle was on. At first it was just JL and M&S, then Boots joined soon after, before Sainsbury's started making big adverts too in 2013 or so. Before long, everyone wanted to be number one, and 2014 was the year that ads truly became a contest. Nowadays, there's a big deal made out of Very or Co-Op ads, which is a bit trivial.
Good history. If you want to go really far back you could say that the first truely anticipated Christmas adverts were for Woolworths in the late 70s and early 80s. Woolworths would get in tonnes of celebrities to star in it and book out entire commercial breaks to show it! No real plot, of course, just some celebs in the store showing off ideal presents like Buzby watches and Binatone TV Tennis Games.
TROGGLES and Night Thoughts gave kudos