Pre 20th century

Sea Mills was the site of a Roman settlement, known as Portus Abonae. Its origin may have been as a military settlement but by the early second century, a civilian town had been established.^[2] It was important enough to feature in the 3rd-century Antonine Itinerary which documents towns and distances in the Roman empire, and was connected to Bath by a road.^[3] Archaeological excavations^[4] have found evidence of the street pattern, shops within the town and cemeteries outside it. The Roman settlement seems to have been abandoned by the 4th century, and there is no evidence of Saxon settlement.^[5]

By the Middle Ages Bristol had become a major port, with all traffic between the port and the sea having to pass through the Avon Gorge and past Sea Mills. In 1712, Joshua Franklyn, a Bristol merchant, built a wet dock at Sea Mills, to eliminate the need for large sailing ships to navigate the dangerous River Avon any further upstream. This was located where the River Trym enters the River Avon. However, poor transport links doomed the enterprise and the harbour facilities fell into disrepair by the end of the 18th century. Some remains of the dock still exist and are used as a harbour by pleasure craft.^[5]

Other industries included agriculture (Sea Mills Farmhouse still exists) and water mills at Clack Mill (a corn mill just below Dingle Road Bridge) and Coombe Mill (for flour production) just beyond the Blaise Estate car park in The Dingle.^[6] Both mills were old and appear on the 1746-1803 mapping on the Know Your Place web site.

• The Clack Mill on the Trym below Dingle Road Bridge. Pen drawing by Samuel Loxton. Picture credit: Bristol Reference Library.

Sea Mills Garden Suburb

After WW1 Sea Mills was one of several areas in Bristol to be developed as municipal housing by the Bristol Corporation under the 1919 housing legislation known as the Addison Act. The Act was designed to address the shortage of quality housing for working people and provide homes for the thousands of troops returning from WW1. Houses built under the Addison Act are often referred to as "homes for heroes".

On 4 July 1919 Dr Christopher Addison visited the building sites at Hillfields and Sea Mills. At Sea Mills he gave a short speech and the Lady Mayoress, Emily Twiggs planted an Oak sapling.^[7] The tree, known as Addison's Oak still stands today and in 2019 was a runner up in the Woodland Trust tree of the year competition.^[8]

The land on which Sea Mills is built was purchased by Bristol Corporation from Philip Napier Miles of Kingsweston House and developed on garden city principles, including building at no more than 12 houses per acre. Building began in 1919 and by October 1920 sixteen houses were already occupied. The early houses were built to the standards specified by the Tudor Walters report, including a parlour downstairs, and three bedrooms upstairs. ^[9]

The suburb includes two small shopping areas, one at Westbury Lane and another on Shirehampton Road featuring a symmetrical arrangement of shops around a green bisected by roads. This is known as Sea Mills Square and is now home to the Cafe on the Square^{[10] [11]} and the Sea Mills mini-museum.^[12] The Square was also once the site of one of the 13 Trench style police boxes which were erected in Bristol in 1932 to serve the suburbs in lieu of new police stations.^[13]

During WW2 a large air raid shelter was provided on Sea Mills Square. For this and other information about the residents see the wartime stories on the Sea Mills 100 web site.^[14]

• WW2 air raid shelter behind No. 83 Coombe Dale. Photo credit: Know Your Place web site

After WW2 a small estate of prefabricated bungalows were built adjacent to the Portway and also in nearby Coombe Dingle.^[15] These have since been demolished.