Why bother with transition between history at Key Stages 2 and 3?

It can sometimes seem that the primary and secondary phases of education live in isolation from each other. After all, most primary teachers are generalists (despite sometimes having specialist experience of a particular curriculum area), having to turn their hands to all subjects on the curriculum whatever they feel about them. Most secondary teachers on the other hand are specialists and prefer to stick to their own area of expertise (which can limit their thinking). Communication across the phases is not always easy. Yet the National Curriculum subjects expect pupils to experience a coherent programme of study spanning from 5 to 16. In addition according to a recently published Ofsted report (September 2015) called ‘Key Stage 3 – the wasted years?’ effective transition arrangements between Key Stage 2 and 3 has never been more important to ensuring pupil progress. Two of its key recommendations are to ensure that ‘transition from Key Stage 2 to 3 focuses as much on pupils academic needs as it does their pastoral needs’ and urges the creation of ‘better cross-phase partnerships with primary schools to ensure that Key Stage 3 teachers build on pupils’ prior knowledge, understanding and skills’. But what has a primary school to gain from such a partnership?