Title: Charles V, Holy Roman Emperor
Content: Margaret of Austria (1522–1586), daughter of Johanna Maria van der Gheynst, a servant of Charles I de Lalaing, Seigneur de Montigny, daughter of Gilles Johann van der Gheynst and wife Johanna van der Caye van Cocamby. Married firstly with Alessandro de' Medici, Duke of Florence, and secondly with Ottavio Farnese, Duke of Parma. ; Joanna of Austria (1522–1530), daughter of Catalina de Rebolledo (or de Xériga), lady-in-waiting of Queen Joanna I of Castile and Aragon. ; Tadea of Austria (1523? – ca. 1562), daughter of Orsolina della Penna. Married with Sinibaldo di Copeschi. ; John of Austria (1547–1578), son of Barbara Blomberg, victor of the Battle of Lepanto Charles and Isabella had seven legitimate children, but only three of them survived to adulthood: Due to Philip II being a grandson of Manuel I of Portugal through his mother he was in the line of succession to the throne of Portugal, and claimed it after his uncle's death (Henry, the Cardinal-King, in 1580), thus establishing the personal union between Spain and Portugal. Charles also had four illegitimate children: 
Title: Coat of arms of Charles V, Holy Roman Emperor
Content:  Charles V, Holy Roman Emperor was the heir of four of Europe's leading royal houses. He first inherited the Burgundian Netherlands, which came from his paternal grandmother, Mary of Burgundy. Charles was then the first sole monarch of Spain, inheriting the kingdoms first united by his maternal grandparents, Isabella I of Castile and Ferdinand II of Aragon (the Catholic Monarchs). Finally, on the death of his paternal grandfather, Maximilian I, Holy Roman Emperor, he inherited the Habsburg lands in Austria.
Title: Charles V, Holy Roman Emperor
Content:  the Handsome, was the firstborn son of Maximilian I of Habsburg, Archduke of Austria as well as Holy Roman Emperor, and Mary the Rich, Burgundian duchess of the Low Countries. His mother Joanna, known as Joanna the Mad for the mental disorders afflicting her, was a daughter of Ferdinand II of Aragon and Isabella I of Castile, the Catholic Monarchs of Spain from the House of Trastámara. The political marriage of Philip and Joanna was first conceived in a letter sent by Maximilian to Ferdinand in order to seal an Austro-Spanish alliance, established as part of the League of Venice directed against the Kingdom of 
Title: Charles VII, Holy Roman Emperor
Content:  Charles and his wife, Archduchess Maria Amalia of Austria, were parents of seven children:
Title: Charles V, Holy Roman Emperor
Content:  During his lifetime, Charles V had several mistresses, his step-grandmother, Germaine de Foix among them. These liaisons occurred during his bachelorhood and only once during his widowerhood; there are no records of his having any extramarital affairs during his marriage. On 21 December 1507, Charles was betrothed to 11-year-old Mary, the daughter of King Henry VII of England and younger sister to the future King Henry VIII of England, who was to take the throne in two years. However, the engagement was called off in 1513, on the advice of Cardinal Wolsey, and Mary was instead married to King Louis XII of France in 
Title: Charles V, Holy Roman Emperor
Content:  Charles V (24 February 1500 – 21 September 1558) was Holy Roman Emperor and Archduke of Austria from 1519 to 1556, King of Spain (Castile and Aragon) from 1516 to 1556, and Lord of the Netherlands as titular Duke of Burgundy from 1506 to 1555. As he was head of the rising House of Habsburg during the first half of the 16th century, his dominions in Europe included the Holy Roman Empire, extending from Germany to northern Italy with direct rule over the Austrian hereditary lands and the Burgundian Low Countries, and the Kingdom of Spain with its southern Italian possessions of Naples, Sicily, and Sardinia. Furthermore, his 
Title: Charles VI, Holy Roman Emperor
Content:  Charles VI (Karl; Carolus; 1 October 1685 – 20 October 1740) was Holy Roman Emperor and ruler of the Austrian Habsburg Monarchy from 1711 until his death, succeeding his elder brother, Joseph I. He unsuccessfully claimed the throne of Spain following the death of his relative, Charles II. In 1708, he married Elisabeth Christine of Brunswick-Wolfenbüttel, by whom he had his four children: Leopold Johann (who died in infancy), Maria Theresa (the last direct Habsburg sovereign), Maria Anna (Governess of the Austrian Netherlands), and Maria Amalia (who also died in infancy). Four years before the birth of Maria Theresa, faced with his lack of male heirs, Charles provided for a male-line succession failure with the 
Title: Charles V, Holy Roman Emperor
Content:  inherited the Burgundian states originally held by his paternal grandmother Mary. In 1516, he became co-monarch of the Spanish kingdoms with his mother, and as such he was the first king of Spain to inherit the country as dynastically unified by his maternal grandparents Isabella I and Ferdinand II. The Spanish possessions at his accession also included the Castilian West Indies and the Aragonese kingdoms of Naples, Sicily and Sardinia. At the death of his paternal grandfather Maximilian in 1519, he inherited Austria and was elected to succeed him as Holy Roman Emperor. He adopted the Imperial name of Charles V as his main title, and styled 
Title: Charles V, Holy Roman Emperor
Content:  encompassed both the long-lasting Spanish and the short-lived German colonization of the Americas. The personal union of the European and American territories of Charles V was the first collection of realms labelled "the empire on which the Sun never sets". Charles was born in the County of Flanders to Philip of Habsburg (son of Maximilian I of Habsburg and Mary of Burgundy) and Joanna of Trastámara (daughter of Isabella I of Castile and Ferdinand II of Aragon, the Catholic Monarchs of Spain). The ultimate heir of his four grandparents, Charles inherited all of his family dominions at a young age. After the death of Philip in 1506, 
Title: Charles VII, Holy Roman Emperor
Content:  Charles VII (6 August 1697 – 20 January 1745) was the prince-elector of Bavaria from 1726 and Holy Roman Emperor from 24 January 1742 to his death. He was a member of the House of Wittelsbach, and his reign as Holy Roman Emperor thus marked the end of three centuries of uninterrupted Habsburg imperial rule although he was related to the Habsburgs by both blood and marriage. After the death of emperor Charles VI in 1740, he claimed the Archduchy of Austria by his marriage to Maria Amalia of Austria, the niece of Charles VI, and was briefly, from 1741 to 1743, as Charles III King of Bohemia. In 1742, he was elected emperor of the Holy Roman Empire as Charles VII and ruled until his death three years later.

Question: Who is the mother of Charles V, Holy Roman Emperor?
Answer: Joanna of Castile.
Joanna.
Joanna the Mad.
Juana of Castile.
Juana la Loca.
Juana I of Castile and Aragon.
Juana I of Aragon.
Joanna I of Castile and Aragon.
Joanna I of Aragon.