Council of Italy in the context of "Supreme Council of Flanders"

Habsburg Spain refers to Spain and the Hispanic Monarchy, also known as the Catholic Monarchy, in the period from 1516 to 1700 when it was ruled by kings from the House of Habsburg. In this period the Spanish Empire was at the zenith of its influence and power. During this period, Spain held many territories, including Pan-American continental holdings and the West Indies; European territories like the Low Countries, Italian territories, Portugal and parts of France; and the Philippines and other possessions in Southeast Asia. The period of Spanish history has also been referred to as the "Age of Expansion".

The Habsburg name was not always used by the family members, who often emphasized their more prestigious princely titles. The dynasty was long known as the "House of Austria". In some circumstances, the family members were identified by their birthplace. Thus, Charles V was known in his youth as Charles of Ghent. As king of Spain, he was known as Charles I of Spain and as emperor, Charles V (in French, Charles Quint). In Spain, the dynasty was known as the Casa de Austria, including illegitimate sons such as John of Austria and John Joseph of Austria. The arms displayed in their simplest form were those of Austria, which the Habsburgs had made their own, at times impaled with the arms of the Duchy of Burgundy (ancient), as seen on the arms of John of Austria. Calling this era "Habsburg", is, to some extent, a convenience for historians.

The War of the Spanish Succession was a European great power conflict, fought between 1701 and 1714. The death of Charles II of Spain in November 1700 without children resulted in a succession struggle between rival claimants. In his will, Charles named his heir as Philip of Anjou, who was backed by his grandfather Louis XIV. His opponent, Archduke Charles of Austria, was supported by the Grand Alliance. Significant related conflicts include the Great Northern War (1700–1721) and Queen Anne's War (1702–1713).

Although no longer the predominant power in Europe, the Spanish Empire remained a vast global power, including the Spanish Netherlands, large parts of Italy, the Americas and the Spanish East Indies. Its union with either France or Austria threatened the European balance of power, and the proclamation of Philip as king of Spain on 16 November 1700 led to war. Although by 1709 the Grand Alliance had forced France onto the defensive, Philip had confirmed his position in Spain, the ostensible cause of the war.

The Iberian Union or the Hispanic Monarchy, describes the period from 1580 to 1640 in which the Monarchy of Spain under the Habsburg dynasty, then the personal union of the crowns of Castile and Aragon, brought in personal union also the Kingdom of Portugal. It incorporated the entire Iberian Peninsula except Andorra, as well as Portuguese and Spanish overseas possessions, under the Spanish Habsburg monarchs Philip II, Philip III, and Philip IV. The union began after the Portuguese succession crisis of 1580 and the ensuing War of the Portuguese Succession, and lasted until the Portuguese Restoration War, during which the House of Braganza was established as Portugal's new ruling dynasty with the acclamation of John IV as the new king of Portugal.

As a personal union, the Kingdom of Portugal, the Crown of Castile and the states of the Crown of Aragon remained independent states, sharing only a single monarch. The kings from the Spanish branch of the House of Habsburg were the only element that connected the multiple kingdoms and territories, ruled by the six separate government councils of Castile, Aragon, Portugal, Italy, Flanders-Burgundy, and the Indies. For periods, Portugal maintained a viceroy, appointed by the king, although the turnover was often rapid; in the 60 years of the Union, the country had 13 viceroys and four regency councils (see List of viceroys of Portugal). Similar viceroys were appointed in Aragon, Catalonia, Valencia and other kingdoms of the Union. The governments, institutions, and legal traditions of each kingdom remained independent of one another. Alien laws (Leyes de extranjería) determined that a national of one kingdom was a foreigner in all other kingdoms.

The Council of Castile (Spanish: Real y Supremo Consejo de Castilla), known earlier as the Royal Council (Spanish: Consejo Real), was a ruling body and key part of the domestic government of the Crown of Castile, second only to the monarch himself.

It was established in 1480 under Queen Isabella I, as the chief body dealing with administrative and judicial matters of the realm. With the 1516 ascension of Charles I (later Charles V, Holy Roman Emperor) to the throne of both Castile and Aragon, the Royal Council came to be known as the Council of Castile because Charles was king of many dominions other than Castile, while the Council retained responsibility only over Castile.

The Council of Aragon, officially, the Royal and Supreme Council of Aragon (Spanish: Real y Supremo Consejo de Aragón; Aragonese: Consello d'Aragón; Catalan: Consell Suprem d'Aragó), was a ruling body and key part of the domestic government of the Spanish Empire in Europe, second only to the monarch himself. It administered the Crown of Aragon, which was composed of the Kingdom of Aragon, Principality of Catalonia (including Roussillon until 1659), Kingdom of Valencia, Kingdom of Majorca and Kingdom of Sardinia. The Aragonese possessions in Southern Italy (Naples and Sicily) were later incorporated into the Council of Italy, together with the Duchy of Milan, in 1556. The Council of Aragon ruled these territories as a part of Spain, and later the Iberian Union.

The Council of Portugal, officially, the Royal and Supreme Council of Portugal (Portuguese: Real e Supremo Conselho de Portugal;), was the ruling body and a key part of the government of the Kingdom of Portugal during the Iberian Union. The council was founded in 1582 by Philip I of Portugal following the model of the Council of Castile. It provided Portugal with a large degree of autonomy from the House of Habsburg.

Apart from administering the Kingdom of Portugal and the Algarves, the council administered Portugal's colonial empire.