Fonds GB 0210 HAFFAN - Hafodgaregog and Trefan Estate Records,

The Trefan estate based in the parish of Llanystumdwy, Caernarfonshire, was established by the 16th century. The estate was subsequently inherited by the Hughes family when Zacheus Hughes, the youngest son of Nanhoron Isaf, married Elizabeth, oldest daughter of John Owen and Jane of Trefan. Their grandson, Zaccheus Hughes (d. 1794) married Jane (1736-1765), daughter and sole heiress of Morris Wynne (d. 1739) of Hafodgaregog.

The Hafodgaregog estate, containing lands in Nanmor and Llandecwyn, Merioneth, and in Llangian, Caernarfonshire, descended in the male line of the Williams family until Morris Williams's heiress, Luce, died an infant in 1723. The estate then passed to her cousin Morris Wynne (d. 1739) from where it passed to the Hughes family.

Zaccheus Hughes, as well as owning Trefan as heir of his father, also owned three farms in Cwm Ystradllyn, the small estate of Braich-y-bib, and the larger estate of Cefn Isaf to the north of Trefan; adding Hafodgaregog to his properties on his marriage to Jane. Zaccheus and Jane's heir was their son, John Wynn Hughes (1760-1795) who married Jane Jones. Jane was a minor when she married and after John Wynn's death the marriage was declared void in 1808 following a lawsuit between Samuel Priestley, whose wife Mary was a cousin of John Wynn Hughes, and the Hughes family. John Wynn and Jane's daughter, Jane Wynn Hughes was deemed to be illegitimate and Mary Priestley became the rightful heir of Trefan. Mary had already inherited the land of Tyddyn Madog Goch on succeeding her father, Owen Jones. Samuel died relatively young and the estates came into the possession of his wife, Mary. In 1821 Mary purchased Bryndu from William Wynne of Peniarth.

When Mary died in 1845, the estate was split up between her two sons. Samuel received Trefan and the bordering lands, while John inherited the Hafodgaregog estate and the three farms in Cwm Ystradllyn.