In 1908 it was accepted in trust by the London County Council and renamed St Marylebone Grammar School. After World War II it recovered. Under headmaster Philip Wayne it developed artistic activities, acquired shared use of playing fields in Sudbury Hill, and established a country base in the village of Forest Green, near Leith Hill. In 1957 the motto ex animo tamquam Deo (from the heart, as from God) was added to the school's crest at the suggestion of the deputy headmaster Kenneth Crook.