The Chronicles of the Chronicles of Narnia on the BBC

The very first adaptation of The Lion, the Witch and the Wardrobe was broadcast on the BBC Home Service in September 1959, as part of their Children's Hour strand. It lasted for 6 40-minute episodes, adapted by pioneering radio producer and writer Lance Sieveking, and as you might expect, nothing is known to survive of it today. (Sieveking's Wikipedia article states that the adaptation he did was of The Magician's Nephew, but this appears to be an error based on a 2005 Guardian article about the forthcoming film.)

The first television adaptation of TLtWatW was for ITV, eight years later (largely missing today, with only two of the ten 15-minute episodes known to survive) - by coincidence, at around the same time the book was being read on Jackanory, which went out just over two months before ITV's serial began transmission, and only a few months after that the very same book was read out on Story Time on the Home Service (read by David Davis, who had produced the 1959 adaptation). Prince Caspian was also the subject of Jackanory a few months later, although it appears to be the last book that was.

There next exists a 1979 animated film, but it looks like this was never broadcast on the BBC (there was a redubbed version for the UK, but it was either on ITV or only released on VHS). So we move on to 1988, and the Schools slot on BBC Radio 4 adapts TLtWatW and The Magician's Nephew as a 10-part serial, adapted by Brian Sibley with, interestingly, Stephen Thorne reprising his role as Aslan from the 1979 animation.

Then, on 13 November 1988, perhaps the best-known BBC adaptation makes its debut, with Alan Seymour's six-episode adaptation of TLtWatW as BBC One's Christmas serial that year (with a documentary on C.S. Lewis the previous week) - amusingly, it appears to overlap with the Radio 4 adaptation by a few weeks! The following winter, Seymour adapted Prince Caspian and The Voyage of the Dawn Treader in the same format (the former receiving just two episodes, the latter four), and in 1990 The Silver Chair was the final book to be adapted.

Brian Sibley's radio adaptations continued, though, and became one of (if not the only) adaptations to cover all 7 books - although The Horse and his Boy wasn't broadcast until 1994 (possibly the wait was because it took that long to become clear they weren't doing any more books for television, although that is just my theory). Prince Caspian followed in 1995, with The Voyage of the Dawn Treader hot on its heels, then The Silver Chair in 1996, and The Last Battle in 1997. (Note that the TV series covered them in original publication order, whereas the radio series favoured the chronological one.) The BBC's television and radio serials are both fondly remembered to this day, and are still widely available on home media.

If there are any questions left here, there is, perhaps, how the Hollywood film series would have handled the "uplifting" ending to The Last Battle had it not been cut short after Dawn Treader...