Erik Aschengreen, an eminent dance critic and scholar who did much to show the international importance and history of Danish ballet while also exploring aspects of French, American and other dance traditions, died on Sept. 9 in Copenhagen. He was 88.
His husband, Per Morsing, said the cause was an aortic rupture. Mr. Aschengreen had been treated for amyloidosis, a rare disease that can lead to organ failure.
No ballet company stays frozen in amber. Yet the Royal Danish Ballet, from the late 19th century to just after World War II, kept an exceptionally large part of its 19th-century repertory and traditions going, though they were scarcely known outside Denmark.
Having been preserved, Danish dance rapidly won acclaim across Europe and in the United States from the late 1940s on. It was during this period that Mr. Aschengreen, then in his teens, began to discover ballet.
Over the ensuing decades he built up expertise and authority. While Danish dancers like Erik Bruhn, Peter Martins, Ib Andersen and Nikolaj Hübbe enjoyed long careers in America, bringing renown to the Danish tradition, and while the Royal Danish Ballet brought its treasured 19th-century Romantic and neo-Classical ballets by August Bournonville to American cities, the larger historical context of Danish ballet became better understood internationally thanks in particular to the work of Mr. Aschengreen, who wrote and lectured in Denmark, the United States and elsewhere.
The 1979, 1992, and 2005 festivals of Bournonville’s ballets flooded the Royal Danish Theater in Copenhagen with dance authorities from many countries. Mr. Aschengreen did much to welcome, entertain and enlighten them as a spokesman at many presentations by the Danish company.
In “The Boy From Kyiv,” her forthcoming biography of the Ukrainian American choreographer Alexei Ratmansky (who is artist in residence at the New York City Ballet), Marina Harss relates how Mr. Ratmansky, when he was a dancer with the Royal Danish Ballet in the late 1990s, made his way to Mr. Aschengreen’s Copenhagen flat in search of videos and books on Danish ballet history; Mr. Aschengreen, she says, was delighted to help him.
From 1964 to 2005 Mr. Aschengreen was the dance critic for the Copenhagen-based Berlingske Tidende (now known simply as Berlingske), one of the world’s oldest newspapers still in print. From 1969 to 2000 he was a professor at the University of Copenhagen, where in 1989 he founded the discipline of dance aesthetics and history.
He also taught ballet history at the Royal Danish Ballet School from 1971 to 1993 and dance history at the Danish School of Contemporary Dance from its founding in 1990. He traveled extensively to see international dance and to investigate dance education.
With the English-language publication of his monograph “The Beautiful Danger” in 1974, Mr. Aschengreen became internationally appreciated for his new vision of Bournonville’s ballets in the context of European Romanticism. That year he began to lecture and teach across the U.S., Canada and Europe. In 1986 he showed that his expertise was not confined to Danish ballet but extended to France as well with the book “Jean Cocteau and the Dance,” about the poet’s links to dance from 1909 until his death in 1963.
In 1998, Mr. Aschengreen brought out “The Dance Is Light: The Royal Danish Ballet, 1948-1998.” (The title refers to an old song quoted in the Bournonville ballet “A Folk Tale,” from 1854.) The book is widely regarded in Denmark as his most important work.
Ib Andersen, the longtime artistic director of Ballet Arizona in Phoenix, wrote in a WhatsApp message on Thursday that Mr. Aschengreen, whom he recalled seeing often on television, had “loved ballet more from a historical point of view than a critic’s point of view.”
Dinna Bjørn, one of the foremost teachers and stagers of Bournonville’s work, remembered Mr. Aschengreen as her oldest friend and called his death a loss “for the whole ballet world.”
Erik Aschengreen was born in Frederiksberg, a suburb of Copenhagen, on Aug. 31, 1935, one of three children of Carl and Else (Hermansen) Aschengreen. His father traded in seeds. Erik lived with his parents in the family home until they died, and he remained there until he was 65. In addition to Mr. Morsing, he is survived by his sister, Dorthe Aschengreen, and a niece and a nephew.
Performances at the open-air Pantomime Theater in nearby Tivoli Gardens inspired Mr. Aschengreen’s love of ballet, which deepened on his first visits to the Royal Danish Theater when he was 13.
In 2000, Mr. Aschengreen moved to an apartment in central Copenhagen lined with books and historic lithographs, and begun concentrating mostly on writing books.
In 2005, he published a biography of the choreography Harald Lander, who directed the Royal Danish Ballet from 1932 to 1951; a book that combined autobiography with an introduction to the art of ballet, examining the classics as he had observed them over 60 years; a second book of memoirs; and “Dancing Across the Atlantic” (2014), in which he described the rich dance relations between the United States and Denmark between 1900 and 2014.
Though ill with amyloidosis and undergoing chemotherapy, Mr. Aschengreen managed to continue to attend performances, most recently two that had meant the most to him: Bournonville’s “La Sylphide” (1836) and Roland Petit’s “Le Jeune Homme et la Mort” (1946). He also entertained visitors until the last two weeks of his life and exchanged emails with friends until the day before he died. When death came, Mr. Morsing was holding his hand.