Coat of arms of Spain applies to jurisdiction Spain
The coat of arms of Spain represents Spain and the Spanish nation, including its national sovereignty and the country's form of government, a constitutional monarchy. It appears on the flag of Spain and it is used by the Government of Spain, the Cortes Generales, the Constitutional Court, the Supreme Court, and other state institutions. Its design consists of the arms of the medieval kingdoms that would unite to form Spain in the 15th century, the Royal Crown, the arms of the House of Bourbon, the Pillars of Hercules and the Spanish national motto: Plus Ultra. The Monarch, the heir to the throne and some institutions like the Senate, the Council of State and the General Council of the Judiciary have their own variants of the coat of arms.
The blazon of the Spanish coat of arms is composed as follows:Historical Spanish coats of arms
The Arms of the Kingdom of Spain was the official coat of arms of the Monarch of Spain from the time of the Catholic Monarchs, and was used as the official arms of the Kingdom until the First Spanish Republic in 1873. Afterwards, the arms became an integral part of the Coat of Arms of Spain. The different governments since (whether republican or monarchist) have led to the arms being changed on various occasions, but always respecting the main heraldic design involving the former kingdoms and, in many cases, the pillars of Hercules.
As a reward for his successful voyage of discovery, the Spanish sovereigns granted Columbus the right to bear arms. According to the blazon specified in letters patent dated May 20, 1493, Columbus was to bear in the first and the second quarters the royal charges of Castile and León, the Castle and the Lion, but with different tinctures or colours. In the third quarter would be islands in a wavy sea, and in the fourth, the customary arms of his family.House of Trastámara
The arms of the Catholic Monarchs, Isabella I of Castile and Ferdinand II of Aragon, whose marriage unified Spain, were:Quarterly, 1 and 4. quarterly Castile-León,
2 and 3. per pale Aragon and Aragon-Sicily.
The arms were borne by the eagle of Saint John, sable, with an open royal crown.
The conquest of Granada was symbolized by the addition enté en point of a quarter for GranadaAfter Isabella I's death in 1504, Ferdinand used different arms, namely tierced per pale Castile-León, Aragon-Naples-Sicily, and Aragon. The annexation of Navarre (1513) brought about the final change in the arms of the Rey Católico (Catholic King): the second quarter was changed to per pale, 1. per fess Aragon and Navarra, 2. per fess Jerusalem and Hungary.
The arms as used in Navarra (until 1700) were Quarterly:House of Bourbon
Philip was born in Versailles. He was made the Duc d'Anjou upon his birth. He was the second son of Louis, le Grand Dauphin.  In the year 1700, the King of Spain, Charles II, died. Charles' will named the 17-year-old Philip, the grandson of Charles' sister Maria Theresa, as his successor.  Upon any possible refusal the Crown of Spain would be offered next to Philip's younger brother Charles, Duke of Berry, or to Archduke Charles of Austria.
Both claimants had a legal right due to the fact that Philip's grandfather, Louis XIV of France and Charles's father, Leopold I, Holy Roman Emperor, were both the husbands of Charles' older half sisters and sons of Charles' aunts.
Philip had the better claim because his grandmother and great-grandmother were older than Leopold's. However, the Austrian branch claimed that Philip's grandmother had renounced the Spanish throne for her descendants as part of her marriage contract. This was countered by the French branch's claim that it was on the basis of a dowry that had never been paid.
After a long council meeting where the Dauphin spoke up in favour of his son's rights, it was agreed that Philip would ascend the throne but would forever renounce his claim to the throne of France for himself and his descendants. It was not difficult to see whether Louis would have refused anyway as a Habsburg ruler in Spain would've put a possible enemy on three frontiers.
The arms of Bourbon-Anjou were added in 1700 when Phillip V became king of Spain. He introduced changes in the royal arms of Spain. The king's new arms were designed by the French heraldist Clairambault in November 1700, and were as follows:
per fess: 1. per pale, quarterly Castile and León, enté en point Granada, and per pale, Aragon and Aragon-Sicily; 2. Quarterly, Austria, Burgundy modern, Burgundy ancient and Brabant; enté en point, per pale Flanders and Tyrol. Overall an escutcheon Anjou. The abbreviated arms were quarterly Castile and León, enté en point Granada, overall Anjou.