The original A47, running between Great Yarmouth and Birmingham, was first designated in the early 1920s.

However, there were some changes made to its route in the early years. At its eastern end, the A47 originally ran through Filby and Caister. The A47 was rerouted along the Acle Straight in 1935.

The A47 originally went via Downham Market, not King's Lynn, but was rerouted via King's Lynn in 1935.

After King's Lynn was bypassed in 1975, pictured, major improvements were made from the late 1970s until early in the 1990s.

The seven-mile £5m Dereham bypass – built on part of a disused railway line – was opened in spring 1978, followed by a five-mile part dual-carriageway Swaffham bypass, costing £5m, which came into use in June 1981. Blofield was then bypassed in 1982.

At the end of the A47, the southern section of the Yarmouth western A12 bypass was opened in May 1985 and the northern part in March 1986 at a cost of £19m.

In 1989, the Acle bypass was completed as a cost of £7.1m.

The £62m Norwich southern bypass was then completed in September 1992.