John Davies. Breaking up the following decade, some of its aspects were later absorbed into Plaid Cymru, such as the use of English and the engagement in English-speaking Welsh communities, echoing calls from Dr D. J. Davies. This was "key ... to the party's increasing acceptability" to voters, wrote Davies. Leading Plaid Cymru members advocated that an independent Wales would be better served by a Welsh constitutional monarchy, one which would engender the affection and allegiance of the Welsh people and legitimise Welsh sovereignty. An hereditary constitutional monarch would, they argued, embody and personify Welsh national identity above party politics, while political parties formed governments in a parliamentary system similar to those of Denmark, Norway, the Netherlands, and Spain. Economist D. J. Davies, originally a republican, wrote an article in Y Faner in 1953, and later published in English in the 1958 book Towards Welsh Freedom, in which he advocated the elevation of a Welsh gentry family as the Royal Family of Wales. Among the criteria for consideration, argued Davies, was that the family had to have a history of contributing to Welsh life and reside in Wales. Davies wrote in 1953 of the Rhys/Rice family of Dinefwr in Carmarthen, suggesting their elevation to a restored Welsh kingship. Author Siôn T. Jobbins suggested the election of a member of the Windsor dynasty for an independent Wales. The flooding of Capel Celyn See also Capel Celyn, Llyn Celyn. In 1956, a private bill sponsored by Liverpool City Council was brought before the UK parliament to develop a water reservoir in the Tryweryn Valley, in Meirionnydd in Gwynedd. The development would include the flooding of Capel Celyn (Holly Chapel), a Welsh-speaking community of historic significance. Despite universal and bipartisan objections by Welsh politicians (thirty five out of thirty six Welsh MPs opposed the bill, and one abstained) the bill was passed in 1957. Evans joined Dr Tudor Jones and Capel Celyn farmer David Roberts, aged 65, at the Liverpool Town Hall to protest, and had to be forcibly ejected by police. The building of the reservoir was instrumental in an increase in support for Plaid Cymru during the late 1950s. Almost unanimous Welsh political opposition had failed to stop approval of the scheme, a fact that seemed to underline Plaid Cymru's argument that the Welsh national community was powerless. At the subsequent General Election the party's support increased from 3.1% to 5.2%.