Llaneilian (; ) is a village and community in Anglesey, Wales. It is located in the north east of the island, east of Amlwch, north west of Menai Bridge and north of Llangefni. The community includes the villages and hamlets of Dulas, Llaneilian, Pengorffwysfa, Cerrig Man and Penysarn, Gadfa and Nebo, and at the 2001 census had a population of 1,192, decreasing slightly to 1,186 at the 2011 Census. The parish is crowned by its hill, Mynydd Eilian (177 metres), a HuMP, popular with walkers and ramblers (the Anglesey Coastal Path navigates most of the parish's coastline - all of which within the Anglesey Coastal Area of Outstanding Natural Beauty), and its beach, Traeth Eilian, which is popular with holidaymakers and for watersport activities. At the north easternmost point is Point Lynas, (on a clear day from the north coast of Anglesey the Isle of Man is visible with the streetlights of Douglas, Isle of Man visible on the horizon), while Ynys Dulas lies off the North East coast of the island, east of Dulas Bay. History Llys Caswallon, Court of the Kingdom of Gwynedd The parish contains the remains of Llys Caswallon and there has been a traditional association of this site with the court of 5th Century King of Gwynedd Cadwallon Lawhir ap Einion - the third generation of the dynasty of Gwynedd, being the grandson of Cunedda, the progenitor of the royal dynasty of Gwynedd. With no visible evidence above ground it had been thought that the site indicated on the Ordnance Survey map of 1889, within a field near Mynnydd Eilian, might be without basis and by the mid 20th century had been largely discredited as a Llys site. However a geophysical survey in 2009 identified foundations of a rectangular building within a trapezoidal enclosure, for which an early medieval site was a strong possibility. The Lineage of Cadwallon led to the famed reign of Rhodri the Great, who brought the kingdoms of Gwynedd, Powys and Seisyllwg under his control, and fought the threats of the Anglo Saxons and Vikings, and who was killed on the island of Anglesey in 854AD. Later, this lineage led to possibly the most well known of all the medieval kings of Wales, Hywel Dda, who came to rule most of Wales, and became synonymous with the codification of medieval Welsh law which became famed for a reputation of justice and