Lajos Tardy was born on July 28, 1914 in Budapest. His father was a mechanical engineer. He graduated in law in 1937 from the Péter Pázmány University. From October 1937 to November 1938, he served in the military. After that, he worked to several law firms as a lawyer candidate. In 1942, he passed a unified judicial and law examination, and thus that year he had the opportunity to open a law office in Pestújhely.
In the World War II he served as a soldier on the Eastern Front, He fell into Soviet captivity, from which he was freed in 1947. Returning to Budapest, he became a lawyer at the Ministry of Agriculture. From January 1949 he worked in the Ministry of Justice as a sub-department head in the rank of ministerial class councilor, and in parallel from November 1949 he was also the director of the National Translation and Certification Office until 12 March 1955.
He was arrested on March 28, 1955, on fabricated charges, and released from prison on October 2, 1955. He then fell ill and was in hospital until 28 January 1956. He was rehabilitated in 1956 and then in 1989 on the basis of a legal protest.
From July 1956 he was a proofreader at the Új Magyar Könyvkiadó. In 1957–58 he worked as an independent lawyer, while in 1959-60 he worked for the State Book Distribution Company. From November 1960 to the end of 1969 he was a researcher at the National Széchényi Library. From 1970 on he worked as the head of the Archaeological Library of the Hungarian National Museum until his retirement in 1975.
He obtained his candidate’s degree in law in 1954 with a dissertation in law, and then, as a Kartvelologist and researcher of the history of Hungarian-Georgian relations, he received a doctorate in history in Georgia in 1973. The topic of his dissertation was “Public opinion regarding Georgia in the Middle Ages and Georgian-Hungarian relations in the 16th century ”).
He was a member of the Prehistoric Working Community of the Hungarian Academy of Sciences and the Prehistoric Working Community of Szeged. He was elected a member of the Oriental Studies Committee of the Hungarian Academy of Sciences, and he was a member of the Kőrösi Csoma Society. He was a member of the Hungarian Writers’ Association, the Hungarian Pen Club, and the board of the Société des Asiatique de Paris, the scientific council of the Revue de Kartvélologie in Paris. He was an honorary professor at the József Attila University of Szeged.
In 1984 he was awarded the István Weszprém Memorial Medal for his research on medical history. He has been awarded the Order of Merit twice. From 1988, he assisted the work of the then-established Historical Justice Committee.
He died on January 10, 1990 in Budapest.