The
Union of Valencia was an anti-royalist movement in the
Kingdom of ValenciaThe Kingdom of Valencia , located in the eastern shore of the Iberian Peninsula, was one of the component realms of the Crown of Aragon. When the Crown of Aragon merged by dynastic union with the Crown of Castile to form the Kingdom of Spain, the Kingdom of Valencia became a component realm of the...
begun in 1283 and lasting into the fifteenth century. The Union was formed in the aftermath of the formation of the
Union of AragonThe Union of Aragon was an anti-royalist movement among the nobility and the townsmen of the lands of the Crown of Aragon during the last quarter of the thirteenth century...
in October 1283. Its essential purpose was as a tool of the Valencian nobility to be used against the influence of
CatalansThe Catalans or Catalonians are the people from, or with origins in, Catalonia that form a historical nationality in Spain. The inhabitants of the adjacent portion of southern France are sometimes included in this definition...
and foreigners on the actions of
the CrownThe Crown of Aragon Corona d'Aragón Corona d'Aragó Corona Aragonum controlling a large portion of the present-day eastern Spain and southeastern France, as well as some of the major islands and mainland possessions stretching across the Mediterranean as far as Greece...
. By 1285 the Unions had severely curtailed the powers of the king and were hindering his efforts in the
War of the Sicilian VespersThe War of the ' Vespers started with the insurrection of the Sicilian Vespers against Charles of Anjou in 1282 and finally ended with the peace of Caltabellotta in 1302...
and against the
Aragonese CrusadeThe Aragonese Crusade or Crusade of Aragon, a part of the larger War of the Sicilian Vespers, was declared by Pope Martin IV against the King of Aragon, Peter III the Great, in 1284 and 1285...
that invaded Catalonia that year.
In 1347 during the
cortesA parliament is a legislature, especially in those countries whose system of government is based on the Westminster system modeled after that of the United Kingdom. The name is derived from the French , the action of parler : a parlement is a discussion. The term came to mean a meeting at which...
of
ZaragozaZaragoza , also called Saragossa in English, is the capital city of the Zaragoza Province and of the autonomous community of Aragon, Spain...
, the Union of Valencia allied with that of Aragon and demanded the right to appoint a
justiciaJusticia is a genus of flowering plants in the bear's breeches family, Acanthaceae. The roughly 420 species it contains are native to tropical to warm temperate regions of the Americas, with two species occurring north into cooler temperate regions...
in Valencia like the Aragonese
Unidos had. They then successfully besieged the royalist castle of Játiva. The Union persuaded
FerdinandFerdinand is a Germanic male given name composed of the words for "prepared"/"protection"/"safety"/"peace" and "journey"/"boldness"/"recklessness"...
to be their lieutenant-general and, with an army of 30,000, he dealt the royalists a second defeat. Then
Peter IVPeter IV, , called el Cerimoniós or el del punyalet , was the King of Aragon, King of Sardinia and Corsica , King of Valencia , and Count of Barcelona Peter IV, (Balaguer, September 5, 1319 – Barcelona, January 6, 1387), called el Cerimoniós ("the Ceremonious") or el del punyalet ("the one...
went from
BarcelonaBarcelona is the second largest city in Spain after Madrid, and the capital of Catalonia, with a population of 1,621,537 within its administrative limits on a land area of...
to Valencia to negotiate with the leaders of the Union. The Aragonese union sent a troop of reinforcements, around 20,000, to Ferdinand. Peter offered to declare Ferdinand his heir, but negotiations broke down. Peter was briefly imprisoned in Morvedre in early 1348; only the arrival of the
Black DeathThe Black Death was one of the most devastating pandemics in human history, peaking in Europe between 1348 and 1350. Of several competing theories, the dominant explanation for the Black Death is the plague theory, which attributes the outbreak to the bacterium Yersinia pestis. Thought to have...
forced his release. When he had again obtained the upper hand, Peter ordered the "great bell" that had been used to rally the
Unidos to be melted and its liquor poured down the throats of the Union's leaders. Peter was even implicated in the death (by poisoning) of his brother
James IJames I , the eighteenth Count of Urgell, was the fourth son of Alfonso IV King of Aragon and Teresa d'Entença & Cabrera, 17th Countess of Urgell.-Biography:...
, Count of Urgell, that year; James had been a supporter of the Union. On 1 November 1348, the Union attacked the
JewsThe Jews , also known as the Jewish people, are a nation and ethnoreligious group originating in the Israelites or Hebrews of the Ancient Near East. The Jewish ethnicity, nationality, and religion are strongly interrelated, as Judaism is the traditional faith of the Jewish nation...
of Morvedre because they, being by law
serfA spin exchange relaxation-free magnetometer is a type of magnetometer developed at Princeton University in the early 2000s. SERF magnetometers measure magnetic fields by using lasers to detect the interaction between alkali metal atoms in a vapor and the magnetic field.The name for the technique...
s of the Crown, were considered
de jure royalists.
In 1401 King Martin granted the Union the right to use the royal flag, the
senyeraThe Senyera is a vexillological symbol based on the coat of arms of the Crown of Aragon, which consists of four red stripes on a golden background...
(actually a likeness of the
penó de la conquestaThe Pennon of the Conquest is the flag raised by the Moors of Valencia, Spain, on September 28, 1238 on the tower of Alī-Bufāt, later called Torre del Temple, to indicate their surrender to the troops of king James I of Aragon...
), with the Union symbol on it.