Yorkshire (see note under this category discussing how the Yorkshire and Great British National Championships relate to each other)
The regionals/nationals contesting format dates from the contest's post-war resumption in 1945, when a three-section national grading system (Championship, Second, and Third Sections) was introduced, with the Fourth section being added in 1947. In 1992 the additional "First Section" was interpolated between the Championship and Second Sections, giving us the current five-section structure.
The contributing regions have mostly remained static since they were laid out, with some exceptions. Between 1985 and 1993 the Midlands area was run as two separate areas, North Midlands and South Midlands. North Wales bands were originally classified in the North West area, but between 1991 and 1994 a separate North Wales area was run. From 1995 (and in some cases a year or two earlier) North Wales bands have competed in the Welsh area. In addition to these structural changes, minor boundary changes have occurred over the years. From 1986 to 1993 bands in Cambridgeshire, Norfolk, and Suffolk were placed in the South Midlands region, afterwards returning to the L&SC region from which they had come. From that year, 1994, Hampshire bands were moved from the L&SC region to the West of England region, and, further North, the then county of Humberside was at the same time attached to the North of England region. This followed an earlier migration of North Yorkshire bands to the same region, both being removed from the Yorkshire region (which was known until the mid 1960s as the North Eastern region).
Prior to World War Two, the National Championship was run as a single festival with multiple sections on the same day, often referred as the Crystal Palace festival. In this format it ran in the years 1900-1913 and 1920-1938.
The first contest in this series was held in 1900, and proved such a success that it was then held annually until 1913. In 1906 it expanded to six sections - Championship, Grand Shield, Junior Cup, Preliminary Shield, Preliminary Cup, and Consolation Cup.
After World War One, the contest resumed in 1920, initially with four sections - Championship, Grand Shield, Junior Cup, and Junior Shield. In 1922 this was expanded to five sections by splitting the Junior Shield into A and B contests, and in 1923 to six by similarly splitting the Junior Cup, with a further expansion to seven sections taking place in 1929 with the addition of a C division to the Junior Shield. In 1938, the final contest before World War Two, the format was again expanded, this time to ten sections, by splitting each Junior Shield section into two, giving rise to section names such as "Junior Shield - B (2)". When the contest resumed in 1945, it was with the quite different regionals/nationals format described above.
The inaugural 1900 contest was not the first British national contest. In the four years 1860 to 1863, impresario Enderby Jackson organised contests of similar scale with the same aim, also attracting bands from across the country to the Crystal Palace, albeit with a somewhat different contesting format, one that involved qualification stages taking place earlier in the day in the same venue.