The Duchy of Dyfed is technically the area around the town of Newport (Pembs). It has at times doubled as the title for the far larger territory of the Duchy of Deheubarth. It was first created by King Hywel I for the brother of his Queen.
Gwilym Powell, son of the Earl of Pembroke was therefore raised to be the first Dug (Duke) within Wales. Such a move as not calculated to impress the other magnates of the realm and Dug Gwilym struggled to impose himself on the political scene. This changed with the death of Hywel and the minority of his heir, Hywel II of Wales. With the Queen Dowager (Eleanor of Pembroke) named as Llywydd (President) of the Council, the Dug was named as her proxy in Council. Their early dominance was ended by the Treaty of Woodstock (signed Oct 29th 1513) but this brief period of importance was enough to cement the Dug's position amongst the Welsh nobility.
Duke of Dyfed (1st Creation)
- Gwillym Powell 1498-1537 - 1st Duke of Dyfed 1498-1537
- Rhys I Powell 1506-1561 - 2nd Duke of Dyfed 1537-1561
With the death of Rhys in 1561 the title of Dug Dyfed reverted back to the Crown and was used by the monarch (Elen of Wales) when her youngest son was married. Prince Rhys was the first Dug to use the Lion of Dyfed as his Ducal Standard.
Duke of Dyfed - 2nd Creation (Subsidary title to the Duke of Deheubarth 1st Creation)When Prince Rhys of Wales married Margaret Howard (niece to the Duke of Norfolk), Queen Elen decided to raise him up to the rank of Royal Duke. Elen created a new title for Rhys, the Duke of Deheubarth. Deheubarth consisted of Dyfed, Ceredigion and Cantref Mawr and such the territory rivalled that of Gwynedd and Powys. Rhys would be the only Dug of this entire territory. Rhys's time as Dug was brief and ended during the Protestant Wars against his brother the king, Marc. Rhys used as his arms the Lion of Deheubarth and was the first since the days of the Lord Rhys to use it as a personal banner.
- Rhys II MacGregor-Glyndwr 1568-1599 - 1st Duke of Deheubarth & 3rd Duke of Dyfed 1587-1591
With the birth of his son and heir, Dafydd, Rhys decided to separate out the Ducal titles. With the consent of the Queen, Rhys gave up the title of Duke of Dyfed, though retaining overlordship of the title. Dafydd was raised to the rank of Royal Duke on his 3rd birthday. Though King Marc tried to remove the rank and title of Duke of Deheubarth from Rhys he ultimately failed in this.
- Dafydd I MacGregor-Glyndwr 1588-1640 - 4th Duke of Dyfed 1591-1600
- Dafydd I MacGregor-Glyndwr 1588-1640 - 2nd Duke of Deheubarth & 4th Duke of Dyfed 1600-1640
- Hywel I MacGregor-Glyndwr 1625-1683 - 3rd Duke of Deheubarth & 5th Duke of Dyfed 1640-1683
- Hywel II Macgregor-Glyndwr 1670-1706 - 4th Duke of Deheubarth & 6th Duke of Dyfed 1683-1706
- Dafydd II MacGregor-Glyndwr 1682-1718 - 5th Duke of Deheubarth & 7th Duke of Dyfed 1706-1718
During the reign of Dafydd V of Wales (Dafydd II of Deheubarth), Dafydd again decided to split the titles of Dyfed and Deheubarth. Raising Owain Mab-Rhys to the dignity of Dug Dyfed.
Duke of Dyfed (3rd Creation)
- Owain Mab-Rhys 1672-1734 - 8th Duke of Dyfed 1705-1734
Owain moved the Ducal Seat back to Trefdraeth, leaving Dinefwr House as a Royal Residence and seat of the Dukes of Deheubarth (Ceredigion & Cantref Mawr). Owain led the Welsh retreat from Milford Haven along with the Prince of Morgannwg and led the first invasion (the invasion of '22).
Owain didn't marry and died in 1734 without issue. The title therefore reverted back again to the crown.
Duke of Dyfed (4th Creation)
- Meurig Tomos-Seislyg 1710-1781 - 9th Duke of Dyfed 1748-1781
- Rhys III Tomos-Seislyg 1743-1825 - 10th Duke of Dyfed 1781-1825
- Pedr Tomos-Seislyg 1768-1844 - 11th Duke of Dyfed 1825-1844
- Meurig II Tomos-Seislyg 1799-1873 - 12th Duke of Dyfed 1844-1873
- Rhys IV Tomos-Seislyg 1827-1906 - 13th Duke of Dyfed 1873-1906
- Rhys V Tomos-Seislyg 1862-1925 - 14th Duke of Dyfed 1906-1925
- Owain II Tomos-Seislyg 1894-1958 - 15th Duke of Dyfed 1925-1958
- Iorwerth Tomos-Seislyg 1920-1994 - 16th Duke of Dyfed 1958-1994
- Meurig III Tomos-Seislyg 1943 - Present. 17th Duke of Dyfed 1994-Present
In 1748 King Rhys raised the minor nobleman, Meurig Tomos-Seislyg to the title of Duke of Dyfed in exile. This grant of title was confirmed by Rhisiart Morgannwg when he was elected to the Crown. Meurig took as his arms the ancient arms of Dyfed and following the reconquest of West Wales returned the Ducal Seat to Trefdraeth though the county town remained that of Abergwaun.