Professor research covered a wide area from ancient ties between Mongolia, India and Tibet to Genghis Khan's Mongolian Empire to Mongolian communism in the 20th century.

From 1987, he served as the General Secretary for the International Association for Mongol Studies and worked as a visiting professor at universities and research institutes in several countries, including the UK, Russia, France, India, and Japan. He wrote books, including the "Mongolian Historiography in the 13th-17th Centuries", and contributed various chapters/volumes to UNESCO's History of Civilizations of Central Asia.

Bira was one of founders and the Honorary President of the International Fund of Tengri Research, President of the Roerich Society of Mongolia, and Director of the Nicholas Roerich Museum and Shambhala Art Institute. He worked with Glenn Mullin to save the Roerich house in Mongolia and restore it as a museum and art gallery. Bira was the oldest living student of George Roerich.

In 2006 he was awarded the Fukuoka Prize. Bira died on 13 February 2022, at the age of 94.

Igor de Rachewiltz (April 11, 1929 – July 30, 2016) was an Italian historian and philologist specializing in Mongol studies. He was born in Rome. In 1947, he read Michael Prawdin's Tschingis-Chan und seine Erben ("Genghis Khan and his Heritage") and became interested in learning the Mongolian language. He graduated with a law degree from a university in Rome and pursued Oriental studies in Naples.

In the early 1950s, de Rachewiltz went to Australia on scholarship. He earned his PhD in Chinese history from Australian National University, Canberra, in 1961. His dissertation was on Genghis Khan's secretary, 13th-century Khitan scholar Yelü Chucai. He married Ines Adelaide Brasch in 1956 with whom he had one daughter.

In 1965 he became a fellow at the Department of Far Eastern History, Australian National University (1965–67), becoming a senior Fellow of the Division of Pacific and Asian History at the Australian National University (1967–94), a research-only fellowship. He published a translation of the Secret History of the Mongols in eleven volumes of Papers on Far Eastern History (1971–1985). He also completed projects by the prominent Mongolists, Antoine Mostaert and Henri Serruys, after their deaths. He became a visiting professor at the Sapienza University of Rome three times (1996, 1999, 2001).

In 2004, he published his translation of the Secret History with Brill Publishers; it was selected by Choice as Outstanding Academic Title (2005) and is now in its second edition. In 2007 he donated his personal library of around 6000 volumes to the Scheut Memorial Library.

Late in his life, de Rachewiltz was an emeritus Fellow in the Pacific and Asian History Division of the Australian National University. His research interests included the political and cultural history of China and Mongolia in the thirteenth and fourteenth centuries, East-West political and cultural contacts, and Sino-Mongolian philology generally.

Igor de Rachewiltz died on July 30, 2016. He was 87.