Chronology, Continuity & Canon are the eternal obsessions of fans of all TV shows, not just fans of Doctor Who. At its simplest, when something is established we don't like it when it's subsequently contradicted. We like to know the exact order when things happen and we pay attention when characters mention things we haven't seen on TV. It has always been part of the fictional reality of Doctor Who that the characters have a life beyond what we see them doing on TV. The inference is that the adventures we see the Doctor having on TV aren't the only ones he has. Question is, what are those adventures and when do they take place? And before you know it, you're off and playing Hunt The Story Gap, trying to track down the places where those non-TV adventures happened. Cue that other eternal hallmark of the fan - The List.

For the TV stories, it's usually the case that Production Order and Transmission Order are the same, so the order you see them in on telly is pretty much the order they happened to the Doctor, though there have been exceptions over the years. In this timeline there are two clear instances where the production team swapped stories for reasons of contrast that clearly should not have been swapped around so I've corrected those here. With the Big Finish audios, arguably Canon since The Night Of The Doctor, it's not always so easy to know where a particular story takes place. I call it Minding The Gaps. In general I adhere to the primacy principle, so if Story A is released before Story B, and they both go in the same Story Gap, then Story A goes in first unless there is clear evidence to the contrary.

The Big Finish audios have to take place in the Story Gaps between television adventures, which are the Primary Texts of Doctor Who. Audio adventures, original novels and comic strips are all Secondary Texts. So, when it comes to continuity, the general principle is that the Primary Text takes precedence unless there's a compelling reason not to adhere to it - The Primacy Principle. If it's clear that there is a run of consecutive adventures taking place then the same rules apply as on Television: if A is released before B, then A takes place before B, unless there is a compelling reason for it not to. I call this the rule of Chronological Sequentialism.

There are instances where the end of one story clearly leads straight into the start of another - Frontios into Resurrection of the Daleks for example - and there is no Story Gap in between. For other stories it's implied that the end of one story leads into the start of another but it's less clear cut. For instance there could be a Story Gap in between the end of Black Orchid and the start of Earthshock but the clear inference is that the one follows on very soon after the other, so the continuity jury is out on that one. To my mind it's sheer common sense as to where the gaps are, be they obvious or implied & inferred.

So in drawing up this chronology, I've only gone by what I've actually heard when listening to the audio when working out where a particular story appears in the Doctor's timeline. Just because a CD release for a particular story says it takes place between two stories that doesn't mean I'll agree with it - I'll listen and come to my own conclusions based only on what I've heard. Of course, some of these placements are inevitably arbitrary as there is no clear guide as to where they go. In those cases I've just picked a spot where it seems to me that it might fit and isn't too similar to the stories around it.

In the case of Five Goes Solo, the Fifth Doctor travelling alone is something we never saw him do on Television. But thanks to Big Finish, there are three identified gaps where Five is travelling on his own. The only problem was that the second gap was identified before the location of the first gap was established. So, the audios that were released before either gap was identified, where do they go?

Before I get to how I finally worked out what goes where, let's list the three gaps we currently have:

FIVE GOES SOLO:

GAP #1: After Arc of Infinity

GAP #2: After The Awakening

GAP #3: After The Veiled Leopard

This is where is gets a bit wibbly-wobbly...

Given that the second gap was identified before the first gap, staying consistent with the idea of Sequentialism means that any audios released prior to the one that established Gap #2 should go in Gap #1. The reasoning behind this is that a release that could go anywhere, for lack of evidence as to where where it should go, can't go anywhere until you know it can go somewhere, and it can only go somewhere when that somewhere has been determined. When an audio has been released that establishes where a somewhere is than anything released before that somewhere was established must go somewhere else, and anything released after that somewhere was established goes in that somewhere...

So anything before The Gathering, the audio that established Gap #2, should go in Gap #1, because that's where it would have gone if Gap #1 had been established before Gap #2 instead of the other way round. Similarly, any Five Goes Solo audios released between The Gathering [September 2006] and The Elite [October 2011] should go in Gap #1, as the latter adventure confirmed that Gap's existence. And finally, anything released between The Elite [October 2011] and And You Will Obey Me [April 2016] should also go in Gap #1 as Gap #3 is only established by the latter audio. Any future releases should go in Gap #3 [after The Awakening] unless there is clear evidence they should go somewhere else.