Maria Anna of Austria

Maria Anna of Austria (Maria Anna Josepha; 7 September 1683 – 14 August 1754) was an Archduchess of Austria as she was a daughter of Leopold I, Holy Roman Emperor. She would become Queen consort and regent of Portugal by her marriage to John V of Portugal. She was the Regent of Portugal from 1742 until 1750 during the illness of her spouse. In Portugal she was commonly known as "Mariana". 
Life.
The fifth of Leopold I, Holy Roman Emperors children by Eleonore Magdalene of Neuburg, she was baptised "Maria Anna Josepha". She was born in Linz as the Austrian royal family had to flee Vienna from the Turkish army which destroyed the capital. Maria Anna was a sister of two future Holy Roman Emperors Joseph I and Charles VI. Through Charles VI, she was an aunt of Empress Maria Theresa. Her first cousins included Elisabetta Farnese as well as Charles II of Spain. 
Marriage.
On 27 October 1708 she married her first cousin John V of Portugal. Both of their mothers were sisters. Maria Anna thus became Queen of Portugal as the wife of the ruling king. She was the mother of six children:
Regency.
In 1742 Maria Anna took over power as regent after her husband suffered a stroke, which left him partially paralyzed. When John V died on 31 July 1750 she gave up power to their eldest son Joseph I of Portugal. She died at he Palace of Belém in 1754. Her body was buried in Lisbon, her heart was brought to Vienna and buried there in the imperial crypt.