The wife of Otto von Habsburg - son of the last Austrian emperor - passed away on Wednesday morning at the age of 85.
The Germany-born royal died at her family home in Poecking, in the state of Bavaria, her family has revealed in a statement.
She had been suffering from heart problems for some time.
Born in 1925 as Princess of Saxe-Meiningen in Wuerzburg, Regina was a social worker before marrying her husband in 1951 (pictured) and moving to his official residence in the Villa Austria.
With Otto, Regina had seven children; two sons and five daughters.
Photo: © Getty Images