BUDAPEST — Draw a triangle on the map of Budapest. At one corner, atop the Millennium Column in Heroes’ Square, rises an angel. A few kilometers away at the apex, built like a boat about to sail into the Danube, stands the Hungarian National Theater.

It is there that Tony Kushner’s Pulitzer Prize-winning play “Angels in America” is on a wildly successful run in a production directed by the Romanian-born American Andrei Serban. But the star and driving force of the play is the National’s artistic director, Robert Alfoldi. Every night, the normally reserved Budapest crowd gives Mr. Alfoldi a standing ovation for his performance as the AIDS-riddled hero, who survives disease, desertion and a visit from a real live angel — who, not coincidentally, looks very much like the seraph on the Millennium Column.

Although it has been two decades since the play, with its very American references to the Reagan era, premiered on Broadway, it may be the biggest hit ever in Hungarian theater history. (It is sold out through June and tickets are being scalped on the black market.) Yet on July 1, Mr. Alfoldi will be replaced as the theater’s artistic director by a man who has sworn to return the theater to its Hungarian roots and make the National “a sacred space.”

The keys to both the play’s success and the removal of Mr. Alfoldi may be found at the third corner of the triangle where the ornate Parliament drips 19th-century Austro-Hungarian hauteur into the Danube.