 During this period one of Douglas's most important secular buildings was designed, St Deiniol's Library, at Hawarden, Flintshire, for W. E. Gladstone and his family.The first phase was constructed between 1899 and 1902, and the library was completed in 1904–06.Around this time the practice was commissioned to work on two churches in association with Gladstone; St Ethelwold's (1898–1902) was a new church at Shotton in Flintshire, and additions were made to St Matthew's at Buckley, also in Flintshire, between 1897 and 1905.