King Philip II (Spanish: Felipe II) of Spain, also known as Philip the Prudent or Philip II of the House of Habsburg, was unarguably the most important ruler in Spanish history. It was under his reign that Spain reached the height of its influence and power, and also of its artistic, literary, and musical excellence. As a result, those years are often referred to as the ‘Golden Age’. He was also named the King of Portugal, King of Naples, Duke of Milan, and lord of Seventeen Provinces of Netherlands at various points of his life. For a brief period, he became the jure uxoris King of England and Ireland through his marriage to Queen Mary I. As a young boy, he grew up studious, grave, and mature beyond his years; his formal education and military training receiving equal attention. At the age of 16, his father made him the Regent of Spain, and in the ensuing years he would be the sovereign of a massive empire that would extend to every continent known to contemporary Europeans, leading to the coining of the expression, “the empire on which the sun never sets”. A fervent Roman Catholic, he launched a largely unsuccessful militaristic campaign against the Protestant England in the later years of his reign. In comparison, his endeavours against France and the Ottoman Empire turned out more productive. The islands of Philippines were named so in his honour.