Yes that was when it was the Labour curriculum.
Labour produced teaching materials (QCA docs) that delivered all the curriculum learning objectives. QCA docs weren't mandatory but most schools followed them, particularly for history, science and geography as they were there and there were so many supporting resources made for them by companies eg museums, educational materials, the bbc.
Tories tore it all up and just gave a curriculum (history is really detailed, art is not at all) but did not specify what years.
Unfortunately it is not actually appropriate to teach history in chronological order (I don't think and as my archaeologist friend says) but most schools didn't know what the hell to do so have done so. Some of the topics are extremely abstract (early man) and others more relatable for young minds.
For the most part staff in individual have had to write detailed plans to deliver content which has been enormously taxing. Or scholar but a scheme in, which is expensive, One of the reasons why teachers went on strike.
You also get the issue with first schools and middle schools where topics are missed or repeated as they've not collaborated properly.