Agop (Martayan) Dilaçar was born in Istanbul in 1895 and held various positions in linguistics during the early years of the Türkiye Republic through institutions, educational activities and publications. Dilaçar completed his education at Robert College and participated in academic, encyclopedic and institutional projects using his proficiency in multiple languages. At the invitation of Atatürk, he attended the Turkish Language Research Society congress in 1932 and subsequently served at the Turkish Language Association and the Faculty of Language, History and Geography at Ankara University. Dilaçar spent most of his life engaged in publications and teaching activities in linguistics and died in Istanbul in 1979.

Agop (Martayan) Dilaçar completed his primary education in American missionary schools in Istanbul and was then admitted to Robert College. There he studied many languages including Latin, Ancient Greek, German, French, Greek and Spanish; his linguistic interests developed during these years. He attended classes taught by Tevfik Fikret and graduated with the New York Science Award.

Dilaçar joined the army as a reserve officer during World War I and served first on the Caucasus Front and later on the Syria-Palestine Front. While stationed in Aleppo and Damascus he worked as an interpreter and was introduced to Mustafa Kemal Pasha during this period. After his military service he held administrative and journalistic positions in educational institutions in Lebanon and later returned to Istanbul where he taught at Robert College.

In the late 1920s Dilaçar moved to Sofia where he taught Old Turkic languages and Ottoman Turkish at Svoboden University. He also published articles in various Armenian and Turkish periodicals. In 1932 he attended the First Turkish Language Congress of the Turkish Language Research Society. At this congress he presented a paper titled “Relations Between Turkish, Sumerian and Indian Languages”. In 1934 he was appointed chief expert at the Turkish Language Association and began teaching at Ankara University’s Faculty of Language, History and Geography in 1936. He held this position until 1951.

Dilaçar was part of the founding staff of the Turkish Language Association established in 1932. Within this institution he conducted research on word etymologies and participated in orthographic and dictionary revisions. From 1952 onward he regularly published articles in the journal *Türk Dili* and served as chief editor at Turkish Encyclopedia until 1969. In 1968 he left the Turkish Encyclopedia to focus on his work titled “Kutadgu Bilig İncelemesi”.

Dilaçar conducted research on the structure development etymology and classification of languages. He authored numerous articles and books on comparative linguistic studies between Turkish and other languages. His major works include:

• The Biopsychological Origins of the Sun Language Theory (1936),
• Western Turkish (1953),
• A General View of the Turkish Language (1964),
• Language Languages and Linguistics (1968),
• An Examination of Kutadgu Bilig (1972),
• Principles of Mother Tongue and Major Applications Outside Türkiye (1978).

Dilaçar died in Istanbul on 12 September 1979 and was buried in the Şişli Armenian Cemetery. In news reports following his death his name was generally referred to as “A. Dilaçar”.