The group posted just the word ‘FIVE’ to their Facebook page on Saturday, inviting thousands of comments, even more ‘Likes’, and not a single clue.

Fans debated the significance of the number.

Some tweeted about re-releases, some about concerts, some about box sets and some about promoting the new iPhone or a follow up to Led Zeppelin IV.

Then after much speculation, the countdown was revealed with the number ‘FOUR’. Apparently they are counting down to a bigger announcement; and it is said the news is set for September 13.

The band has quiet of late, and have not really been in the public eye bar performances with associated acts like singer Robert Plant’s Band of Joy and bassist John Paul Jones’ Them Crooked Vultures

Guitarist Jimmy Page's manager, Peter Mensch tweeted the following on Saturday, hinting at their 2007 show: "It's almost here. I've seen it and heard it. almost 5 years to the day." Mensch was even more direct in a post this July: "Today, [producer/engineer Alan] Moulder continues with his stellar mixing of the O2 show. it's been 5 years coming and it's almost here."

Led Zeppelin, although only active for a decade, are considered the founders of modern rock, with Page, Plant, Jones and Bonham having written themselves into rock history as one of the best bands to have ever existed.

Started in 1968 out of what used to be The New Yardbirds, they are one of the best-selling music artists in the history of audio recording with various sources estimating  the group's sales at more than 200 million or even 300 million albums worldwide.

Bonham – who died in 1980 from choking on his own vomit – is rated the best drummer of all time by Rolling Stone readers, Jones at No. 6 in the bassist category, and Plant at the singers No. 1 spot. Page is currently at No. 9 of Rolling Stone’s Top 100 Guitarists of All Time.