Dolbadarn Castle. Dolbadarn Castle is a fortification built by the Welsh prince Llywelyn the Great during the early 13th century, at the base of the Llanberis Pass, in northern Wales. The castle was important both militarily and as a symbol of Llywelyn's power and authority. The castle features a large stone keep, which historian Richard Avent considers the finest surviving example of a Welsh round tower. In 1284 Dolbadarn was taken by Edward I, who removed some of its timbers to build his new castle at Caernarfon. The castle was used as a manor house for some years, before falling into ruin. In the 18th and 19th century it was a popular destination for painters interested in Sublime and Picturesque landscapes. It is now owned by Cadw and managed as a tourist attraction, and is protected as a grade I listed building. Dolbadarn Castle was built in either the 1220s or the 1230s by Llywelyn the Great, at the base of the Llanberis Pass, overlooking the lake of Llyn Padarn in northern Wales. Traditionally the Welsh princes had not constructed castles, instead using undefended palaces called llysoedd, or courts. From the late 11th century onwards, the Normans had advanced into Wales, taking lands in the north and establishing a band of occupied territory in the south called the Welsh Marches. During the 12th century some timber and earthwork castles began to be built, but in small numbers. Llywelyn the Great initially controlled the princedom of Gwynedd, but grew more powerful over the course of his reign, extending his influence over much of Wales during the early years of the 13th century. Llywelyn was faced by several challenges, including dealing with the threat from the kings of England, and maintaining his authority over the native Welsh. As part of this strategy, Llywelyn built Castell y Bere, an innovative stone Welsh castle, in the 1220s. Shortly afterwards he began the first phases of Dolbadarn Castle, constructing the initial stone fortifications on the site, including two square stone towers. The location of the castle was important both because it controlled an important mountain pass, and possibly because Llywelyn claimed authority as the lord of the mountains and coasts of Wales: several of his castles appear to have been located with such political symbolism in mind. It is also possible that Llywelyn may have built his castle on top of the remains of a previous fortification constructed by Maelgwn Gwynedd, a king of Gwynedd in the 6th century, although no such remains have been found. As part of his strategy for dealing with the Marcher Lords, Llywelyn married his eldest son, Dafydd, to Isabella, the daughter of William de Braose, a powerful lord in Brecon, Builth and Abergavenny. The Marcher Lords had adopted a style of stone castle that included circular keeps and an integrated system of curtain walls. Following Dafydd's marriage, Llywelyn appears to have started a second phase of building at Dolbadarn, probably in the 1240s, adding these elements to the existing castle. The prince was probably aiming not only to incorporate the latest military technology, but also to create a castle of equal prestige to those of his new allies in the south. Traditionally the surrounding district of Is Gwyrfai had been run from the town of Llanbeblig; after the 1240s, this role was transferred to Dolbadarn. Following Llywelyn's death in 1240, Gwynedd's power declined and many of its eastern lands were taken by Henry III of England in 1247. Llywelyn's grandson, Llywelyn ap Gruffudd, took power in 1255 and imprisoned his brother Owain ap Gruffudd before extending his power across Wales. Owain was eventually released in 1277 and there has been much historical debate over which castle he was held in. Hywel Foel ap Griffri wrote a famous poem describing Owain's long imprisonment in a round tower; historians believe that this refers to the keep at Dolbardarn. The conflict between the Welsh princes and the English kings continued in the reign of Edward I. In 1282 Llywelyn fought a final campaign against Edward, ending in the prince's death near Builth that December. His brother, Dafydd ap Gruffydd, assumed power but during 1283 was forced south into Snowdonia and by May his government was based from Dolbadarn Castle. Edward deployed 7,000 troops to detain Dafydd who was finally captured and executed in October; Dolbadarn was occupied by Norman forces. Edward was determined to prevent any further rebellion in North Wales and set about building a sequence of new castles and walled towns, replacing the old Welsh administrative system with a new principality governed from Caernarfon. Dolbadarn was no longer relevant and within two years timber from the castle was being used by the Normans for the construction of Caernarfon Castle.