 According to the Palace Law, Prince Prajadhipok, the only surviving full brother of King Vajiravudh via bloodline of Queen Saovabha Phongsri, was then the next in line to the throne.Prince Mahidol Adulyadej became second in line (although older than Prince Prajadhipok, he was son of Queen Savang Vadhana).Third and fourth in line would be his two sons