Böhm has continuing popularity in many countries for his appearance as Emperor Franz Joseph in three 1950s "Sissi" movies (edited down to "Forever My Love" for the US market) alongside Romy Schneider in the title role. To an international audience he may be better known for his appearance as "Peeping Tom" and as Jacob Grimm in George Pal's "The Wonderful World of the Brothers Grimm".
Böhm (son of conductor Karl Böhm) devoted the last four decades to development work (and stopped acting altogether) and realized a remarkable number of projects in this area. He died last Thursday.
Sorry to hear of this. His Peeping Tom is of course indelible. The Sissi films are virtually unknown in the USA, though they were evidently popular in Europe. Americans of a certain age may best remember this actor for playing none other than Ludvig van Beethoven in a Disney two-parter of 1962, THE MAGNIFICENT REBEL. I think it had a theatrical release in Europe.