Philip IV of Spain was King of Spain and Portugal as Philip III . He ascended the thrones in 1621 and reigned in Spain until his death and in Portugal until 1640. Philip is remembered for his patronage of the arts, including such artists as Diego Velzquez, and his rule over Spain during the challenging period of the Thirty Years War.
Philip IV was born in Valladolid, and was the eldest son of Philip III and his wife, Margaret of Austria. In 1615, at the age of 10, Philip was married to 13yearold Elisabeth of France, although the relationship does not appear to have been close some have even suggested that Olivares, his key minister, later deliberately tried to keep the two apart to maintain his influence, encouraging Philip to take mistresses instead. Philip had seven children by Elisabeth, but only one son, Balthasar Charles, who died at the age of sixteen in 1646. The death of his son deeply shocked the king, who appears to have been a good father by the standards of the day. Elisabeth was able to conspire with other Spanish nobles to remove Olivares from the court in 1643, and for a brief period she held considerable influence over Philip by the time of her death, however, she was out of favour, following manoeuvering by Olivares successor, Luis de Haro.
Source: Wikipedia