Its a tricky issue. I am also a Trainee but I have been thinking about this. It is impossible to teach the 'Grand Arch' of history, there is simply too much to teach. I do however think there are better ways to link periods that we teach. Children struggle with the concept of chronology anyway. For quite a long time they see in very black and white terms, past and present. They also equate the passage of time with progress, which we know is not always the case. For this reason I think that the exsistence of gaps isnt as big a deal as it is sometimes made to be....and it is unavoidable anyway. I think my covering broad topics like the Roman Empire and Medieval Period we begin to teach them about Chronology in a compartmentalised way which they can then apply to a wider time period when they are ready.