did he construct any cemeteries and memorials during the war?
Yes, he expanded the existing cemeteries.
Charles Holden
 He travelled to the French battlefields for the first time later that month and began planning new cemeteries and expanding existing ones. Holden described his experience:
who is charles holden? An English architect. when was he born? 12 May 1875. who was he born to? Joseph and Ellen Holden . where did he finish his studies from? He attended many schools and also attended classes at YMCA. which were some of his famous works? The City of London Plan. who were the first settlers of this place? The Roman legions. what is the motto of this city? ""Domine dirige nos"" . and what does that mean? "Lord, direct us". does this city have any gardens? There are many gardens ,like the one in Finsbury Circus. can you name some historical buildings found here? Monument to the Great Fire of London , St Paul's Cathedral, the Guildhall, the Royal Exchange, Dr. Johnson's House and more. how did the architect contribute during the war time? During the war, he was a a temporary lieutenant with the army's Directorate of Graves Registration and Enquiries.
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Charles Holden [SEP] War cemeteries and memorials
From 1918 until 1928 he worked on 69 Commission cemeteries. Initially, Holden ran the drawing office and worked as the senior design architect under the three principal architects in France and Belgium (Edwin Lutyens, Reginald Blomfield and Herbert Baker). Holden worked on the experimental war cemetery at Louvencourt and, according to Geurst and Karol, probably on the one at Forceville that was selected as the prototype for all that followed.