Historical Background
When Britain's main line railways were taken into public ownership in 1948, the newly nationalised concern, British Railways, inherited the steam locomotive design criteria established by the four principal private companies which hitherto had operated by far the bulk of the network (in descending order of size: London Midland and Scottish, London and North Eastern, Great Western and Southern Railways), generally known as the 'Big Four'. Although these companies all had outstanding orders on hand for their existing company designs, duly delivered by the new BR organisation down to 1951, the need was felt for new standardised types which embodied the best practices from all four of them.
In a sense, there was no real need for this policy, since the pre-1948 railways had often achieved a high degree of efficiency in many of their more modern designs which could well have continued to be built as long as further steam locomotives were needed, all things being equal. But there were several other factors in play which, in the event, proved to be rather more significant, of which the first may well have been the psychological dimension.
Britain's railwaymen were traditionally conservative (with a small 'c') and there were numerous examples from history where, usually following the amalgamation of two or more smaller private companies, the design criteria of but one of them was adopted, with little or no debate, for the newly enlarged concern. This did not always go down too well, nor did it always encourage the building of a new corporate spirit after any such amalgamations. The 1923 grouping of the railways into four big systems from many smaller private companies was, perhaps, the best example of this sort of thing, but it was not unique and the new BR locomotive chiefs (some of whom had experienced the problem at first hand a generation earlier) were acutely aware of the difficulties which the offering of one company's design to work the routes of what had hitherto been a different concern might well cause. It was therefore felt that new standard types, different from anything previously seen and, moreover, whose design details could be spread between the principal drawing offices and workshops of all the previous companies rather than be confined to just one of them, would go a long way to resolve this particular problem. In this appraisal, the new BR team was largely correct.
But there were other factors too, for at the time, Britain was still emerging from a long period of wartime and post-war austerity. Against this background, the need was for strictly utilitarian and easy to maintain designs of rather less complexity than some of the existing company types (no matter how efficient), whose origins often dated back to more spacious days, were more sophisticated in consequence and needed better handling and maintenance than could always be guaranteed in early BR days. Things got better in due course, but it should always be remembered that the BR standard steam classes were designed against specifically utilitarian criteria and in most cases intended for a wide range of mixed traffic working rather than being confined to the more dedicated types of operation - e.g. express passenger. And in this context it is interesting to note that where a pre-BR company design had managed to display a similar measure of easy operation and maintenance, it quite often formed the basis of a new BR standard type, sometimes very little changed.
That said, however, it can be no surprise that the first design to appear, the 'Britannia' 4-6-2 type and the subject of this model, was something completely new, owing little in appearance or concept to any of its near-equivalent company types. In a sense, it had to be, given the need to establish a fresh BR philosophy and it made much sense at the time. For one thing, it was Britain's first ever two-cylinder 4-6-2, while its distinctly new visual lines immediately attracted notice, if only because they differentiated it from all previous company designs. It was also the nearest which BR ever came to building a dedicated express passenger type (apart from a solitary and somewhat experimental Class 8 4-6-2 in 1954) and was fully in accordance with historical precedent in the sense that a new team always likes to start with its most glamorous product...
There were eventually 55 of them and they took their class name from that of the first to appear, No.70000 Britannia, in 1951. They were officially classified as mixed traffic and were, in consequence, given 6ft 2in. driving wheels rather than the larger diameters usually preferred for overtly express types. But they very soon became employed almost universally on express passenger workings throughout the country. Their reception was varied and some areas did not like them at all - usually where the 'home' product was every bit as good as the new design - conservatism again? But where they were allocated to areas which had hitherto had to make use of rather less effective types (e.g. the main lines into East Anglia from Liverpool Street) they were adopted with great enthusiasm and did some fine work.
Overall, though hardly ground-breaking by comparison with some other steam designs, the 'Britannias' became good and reliable locomotives after a short initial period of teething roubles in the early 1950s (not unheard of with a totally new type) and outlived almost all their genuine 'express passenger' contemporaries in terms of main line duties. Even so, and like most latter-day steam types, they did not reach their design lifespan (nominally 30 years) but they did survive to see the end of BR main line steam in 1968 and one of them, the subject of this model, achieved semi-iconic status in so doing.

A short history of No.70013 Oliver Cromwell
When it first appeared in May 1951, No.70013 was merely the fourteenth of the first batch of 'Britannias' to be built and went immediately to Norwich when new - an appropriate place in view of the East Anglian origins of its historical namesake. Here it formed one of the group of 'Britannias' which revolutionised services during the 1950s and even after the workings into Liverpool Street had mostly been handed over to the later Type 4 diesels, it continued to work cross-country passenger services on the Eastern Region from the depot at March, to where it was transferred in 1961.
Its sojourn at March was relatively brief and it eventually moved to Carlisle in 1964 after the official decision was made that the last outposts of steam should be dominantly in the NW of England. Here it joined many other surviving 'Britannias' and, if truth be told, was one of many steam locomotives in the area more renowned for their unkempt appearance than for anything else - signs of neglect were all around. But paradoxically, it was at just this nadir in its fortunes that things began to change. By 1966, almost all the 'Britannias' had been withdrawn but 70013 and 70014 were still left at the end of that year and Oliver Cromwell itself was not only the last of its type to be given a full works overhaul at Crewe, but also the last steam locomotive of any class to be given a proper overhaul at that place. It was, accordingly, given a special finish and used for a variety of special and excursion duties thereafter, thus becoming far better known and popular than at any previous time in its life.
By now, the original member of the class, No.70000 Britannia itself, which had been long set aside for official preservation, was found to be in very poor condition and the decision was made that 70013 should take its place. This was determined on the basis that since it was the design itself which was being preserved rather than any one individual member, the far better condition of 70013 made it a more sensible choice for the National Collection. By very good fortune, the pioneer 70000 was also privately preserved, but it was 70013 which achieved the distinction of heading BR's last ever official steam-hauled train on August 11th 1968. After that, its future was assured and in due course, it was sent on loan to the Bressingham Steam Museum in Norfolk - close by its former stamping ground and its first shed at Norwich.
While at Bressingham, it was occasionally steamed at that site, but although there was talk of recovering it for main line work, given the more positive attitude to the operation of preserved steam on the main line in the 1980s and 1990s, nothing transpired. However, at the time of writing (early 2004) a decision has been made that it will be recovered to the National Railway Museum at York in time to participate in an exhibition to celebrate the 200th Anniversary of Richard Trevithick's first ever steam locomotive in 1804. Furthermore, an appeal to raise funds for a full main line overhaul has also been launched and if all goes well, the real 70013 may well be seen on the main line once again.