Rudolf II, Holy Roman Emperor
At the age of two, Isabella was promised to marry her cousin Rudolf II, Holy Roman Emperor (18 July 1552 – 20 January 1612), son of her aunt Maria. However, Isabella had to wait for more than 20 years before the eccentric Rudolf declared that he had no intention of marrying anybody. Meanwhile, she served as her father's primary caretaker during the last three years of his life, when he was plagued by gout and frequent illness.