"Mariana of Austria or Maria Anna (24 December 1634 – 16 May 1696) was Queen of Spain from 1649 until her husband and uncle, Philip IV, died in 1665. She was then appointed regent for their three-year-old son Charles II, and due to his ill health remained an influential figure until her own death in 1696.
Her regency was overshadowed by the need to manage Spain´s post-1648 decline as the dominant global power, internal political divisions and the European economic crisis of the second half of the 17th century. The inability of her son Charles to produce an heir led to constant manoeuvring by other European powers, which ultimately ended in the 1701 to 1714 War of the Spanish Succession." - (en.wikipedia.org 03.10.2020)