Didcot is a town in the Thames Valley, in the English county of Oxfordshire (although formerly in Berkshire). The town is located approximately 8 miles south of the city of Oxford. The district in England with the highest healthy life expectancy, according to the Office for National Statistics study, is the 1990s-built Ladygrove estate in Didcot. Didcot dates back to the Iron Age. The settlement was situated on the ridge in the town, and the remainder of the surrounding area was marshland. The Romans attempted to drain the marshland by building the ditch that runs north through what is now known as the Ladygrove area north of the town near Long Wittenham. Didcot first appears in historical records in the 1200s as Dudcotte, Berkshire. The name is believed to be derived from that of the local Abbot. Didcot was then a sleepy rural Berkshire village with a population of 100 or so, and remained that way for hundreds of years, only occasionally cropping up in records. Parts of the original village still exist in the Lydalls Road area and part of All Saints church dates back to the eleventh century. It was much smaller than several surrounding villages, who are now dwarfed by modern Didcot. There are a number of major scientific employers nearby including the UKAEA at Culham (and the Joint European Torus (JET) fusion research project), Harwell Laboratory, the Science and Technology Facilities Council (the research council responsible for Rutherford Appleton Laboratory) and the Diamond Light Source synchrotron, which is the largest UK-funded scientific facility to be built for over 30 years. Didcot is also the base of operations for the Baptist Union of Great Britain and BMS World Mission. More on Didcot