Henry Max Hoenigswald was born on 17 April 1915 in Breslau named as Heinrich Max Franz Hönigswald, Germany (now Wroclaw, Poland) and died on 16 June 2003 in Haverford, Pennsylvania. He was Professor of Linguistics at the University of Pennsylvania (1948–85; Emeritus). He married Gabriele Schoepflich in 1944 (she died in 2001; they had two daughters),
He was educated in the German Gymnasium, where he learned the classical languages, and trained as an Indo-Europeanist and a historical and comparative linguist in universities in Munich, Zurich, Padua, and Florence. His refugee status compelled these moves (his grandparents were Jewish, and by 1933 Jews were forbidden to attend German universities). In 1939 he escaped to the United States, where he was at first a research assistant at Yale. He taught at the University of Pennsylvania from 1948 until his retirement in 1985. He was a member of the Linguistic Society of America, of which he was elected President in 1958, and a member of the American Philosophical Society for more than 30 years. He was elected to the National Academy of Sciences. He spent a year at Oxford in 1976 and was elected a Corresponding Fellow of the British Academy in 1986.
His arrival in the United States meant not only an end of political oppression but also working contact with scholars who were establishing linguistics as a science, notably Zellig Harris. Deeply familiar with the solid work done by historical linguists, but skeptical by nature, he rapidly came to question their stated rationale and justification for these results, "the gap between substantive practice and theoretical preachment". His work included on the one hand specific penetrating studies in Indo-European and Classical linguistics, and on the other fundamental work in the theory of historical linguistics, some of the first and most lastingly important attempts at formalization of the techniques of historical comparison and reconstruction.