No. Isabella of Castile was member of the Trastamara line, as her husband Ferdinand of Aragon. Her daughter, Juana, was the last Trastamara member who ruled in Spain. After she, her son, Charles I of Spain and V of the Holly Roman Empire was the first Habsburg monarch of Spain. His father was Philip of Habsburg, known as Philip the Handsome, son of the emperor Maximilian and heir of Burgundy.

i believe it was Philip II of Spain

Spain did not control the eastern half of South America, all of North America north of the US American Southwest, nearly all of Africa, and nearly all of Asia (except for the Philippines). Additionally, when the Habsburg Monarchy split, the Spanish government lost control of most Non-Iberian Habsburg European Territories.

King Philip II (1527 - 1598) is generally considered to be the most powerful Habsburg King of Spain.

France wanted to avoid the feeling of geographic encirclement by these two Habsburg Empires.