Demetrius Plato Semelas was born on 2/14 May 1884, in Silyvria, Thrace, and studied at the French and Commercial School of Constantinople.
Immediately afterwards (~1900), due to financial difficulties, he went to Cairo, Egypt to work. At the same time, he engaged in the study of the ancient Egyptian culture in order to subsequently bring out its unknown aspects.
At the age of about 19, after serious spiritual experiences, he moved to Athens (Greece), where he began to study medicine. During his stay there, he discovered in a transcendental way his special mission, which was to revive the work of social regeneration of human society. He undertook and served this mission with complete dedication until the end of his life (1924).
In 1910, Demetrius Semelas was in Cairo, Egypt, where he met the couple Eugene Dupré and Marie Routchine-Dupré, who had come from France and became associated with them with deep spiritual ties.
In 1914, Demetrius Semelas set up the ‘Council of Brotherhood’, gathering around him seven associates and drafting the ‘Universal Code’, a ‘charter’ of principles and ideas for a global social reorganisation and rebirth.
From 1910 he worked closely with Marie Routchine-Dupré to found the Order of the Lily and the Eagle (O.L+E).
After the death of Marie Routchine-Dupré (1918), Demetrius Semelas took over the administration of the O.L+E. He merged in it his own work and reconstituted it on a new statutory basis (1919), in accordance with her wishes.
For five consecutive years he worked for the O.L+E, personally instructing his disciples and enriching it with original and inspiring teachings, laws and mystagogique rituals.
Master Demetrius Semela, worn out by overwork and by a severe chronic tuberculosis, breathed his last in the Sanatorium of Durtôl, France, on August 6, 1924, at the age of just 40. His funeral was held on 9 August in the Orthodox Church of St. Stephen in Paris. He appointed as his successor to the leadership of the Order of the Lily and the Eagle, by a written will, Eugene Dupré, who continued with devotion and consistency the initiatory and social work of the Order.
The O.L+E, through regular succession, is still in operation today.