In the spring of 1927, Queen Marie made an official visit to the United States. During her absence, Helen and her sister-in-law Elisabeth took care of King Ferdinand I, whose health declined rapidly. The king died on 20 July 1927 at Peleș Castle and his 5-year-old grandson succeeded him under the name of Michael I while the Regency Council took over the direction of the country. However, in Romania, Carol retained many supporters (soon nicknamed "Carlists") and the National Liberal Party began to fear the return of the Prince.