 So, in 1909, Ziller was again commissioned to design an extension which was used as a ballroom and is now named the Credentials Lounge.Another extension was needed when Princess Sophia of Greece (now queen of Spain, and daughter of King Paul and Queen Frederica) became engaged to Juan Carlos I of Spain.In 1962, the King commissioned architect Alexander Baltatzis to design an addition which became the largest room in the palace and is now named the Reception Hall.