The earliest record of anyone living at Dôl Llys is of Gruffydd, or Griffith, the fifth son of Owen Gwynn of Llanidloes. It is likely he acquired the property through his marriage to Angharrad, daughter and heiress of Evan ab Jenkyn Glyn ab Evan Lloyd, but leaving behind him only 3 daughters as co-heiresses, the name of Gwynn soon ceased to be connected with Dôl Llys.
The estate descended through the female line with the family name changing to Owen around 1660 and was passed onto the Mears family in 1750. This was a very influential family who moved to the locality from Brecon and increased the size of the estate. George Mears was sheriff in 1759 and his son, Hugh, was sheriff in 1781.
Maurice Mears, who died on 23rd August 1807 aged 73 years, made a very peculiar will which was prepared by Mr. Stephens a local solicitor. In it Mr. Mears named eleven individuals, who upon certain conditions were entitled to inherit the property. His lawyer suggested that he should add an additional name to ‘make it a complete dozen’. Mr. Mears decided to take up the suggestion and told the solicitor to add either his own name or that of his son. The son’s name was added, and strange as it may seem, the other eleven died prematurely and Stephens junior, a young lawyer, inherited the property and without delay changed his name to Mears. He had already been mayor of Llanidloes at the age of 25.
Shortly after inheriting the estate, George Mears (previously George Stephens) built the hall at Dôl Llys between 1808 and 1813. In 1812 he was a J.P. and sheriff.
George Mears died on 25th April 1836 at the age of 66 and the property was divided between his brother the Rev. John Stephens, vicar of Llandinam and his son George, who succeeded at Dôl Llys but died at the early age of 34.
The property was left to George Brookes Mears. He and his heirs were financially crippled by the Welshpool Bank crash and so sold the estate to Edward Morris of Oxon near Shrewsbury in 1865. Some of the money from the sale went to fund the building of Welshpool town hall.