Prince Constantin Jean Lars Anthony Démétrius Karadja[1] (24 November 1889 in The Hague – 28 December 1950 in Bucharest) was a Greek-Romanian diplomat, barrister-at-law, bibliographer, bibliophile and honorary member (1946) of the Romanian Academy.

They had two children: Barrister at law in England with studies at Framlingham College[2] and the Inner Temple,[3] he spoke English, Swedish, Romanian, German, French, Danish and Norwegian, as well as Latin and Greek.

[4] Being accredited as consul general in Berlin and in parallel to his diplomatic activities, he continued his research concerning incunabula, realising in this period the "List of incunabulum on the Romanian territory".

He did not cede in front of political pressures, "doctrines" en vogue or potential "opportunities", but engaged himself with perseverance in the protection of the rights of Romanian citizens living abroad, regardless of ethnicity or religion.

"Tens of thousands owe their lives to his exceptional persistency, abnegation, determination and amplitude marking his long-term engagement in favour of the Romanian Jews stranded under the Nazi regime.

"[11] Yosef Govrin, former Israeli ambassador, also writes that it "required extraordinary courage to act as he did through diplomatic means" as he was putting his career in consequent jeopardy.

On 15 September 2005, Constantin Karadja received from the Yad Vashem institute in Jerusalem posthumously the title "Righteous Among the Nations"[14] during a ceremony in the Israeli embassy in Berlin and in presence of the Romanian ambassador.

They are the means by which Karadja saved over 51,000 persons from deportation and extermination—Jews (men, women and children) from parts of Europe dominated by the Nazis, especially from Germany, France and Hungary, but also from Greece and Italy (November 1943 – July 1944).