Question: When was the Palau de la Generalitat constructed in the city where Martin of the region where Layana is located died?

Knowledge 1: Layana
Layana is a municipality located in the province of Zaragoza, Aragon, Spain. According to the 2004 census (INE), the municipality has a population of 120 inhabitants. [SEP] Knowledge 2: Martin of Aragon
Martin the Humane (29 July 1356 – 31 May 1410), also called the Elder and the Ecclesiastic, was King of Aragon, Valencia, Sardinia and Corsica and Count of Barcelona from 1396 and King of Sicily from 1409 (as Martin II). He failed to secure the accession of his illegitimate grandson, Frederic, Count of Luna, and with him the rule of the House of Barcelona came to an end. [SEP] Knowledge 3: Valencia
Valencia has experienced a surge in its cultural development during the last thirty years, exemplified by exhibitions and performances at such iconic institutions as the Palau de la Música, the Palacio de Congresos, the Metro, the City of Arts and Sciences (Ciutat de les Arts i les Ciències), the Valencian Museum of Enlightenment and Modernity (Museo Valenciano de la Ilustracion y la Modernidad), and the Institute of Modern Art (Instituto Valenciano de Arte Moderno). The various productions of Santiago Calatrava, a renowned structural engineer, architect, and sculptor and of the architect Félix Candela have contributed to Valencia's international reputation. These public works and the ongoing rehabilitation of the Old City (Ciutat Vella) have helped improve the city's livability and tourism is continually increasing.
Knowledge 1: Layana
Layana is a municipality located in the province of Zaragoza, Aragon, Spain. According to the 2004 census (INE), the municipality has a population of 120 inhabitants. [SEP] Knowledge 2: Martin of Aragon
Martin the Humane (29 July 1356 – 31 May 1410), also called the Elder and the Ecclesiastic, was King of Aragon, Valencia, Sardinia and Corsica and Count of Barcelona from 1396 and King of Sicily from 1409 (as Martin II). He failed to secure the accession of his illegitimate grandson, Frederic, Count of Luna, and with him the rule of the House of Barcelona came to an end. [SEP] Knowledge 3: Josep Domènech i Estapà
His works in Barcelona include the church of Sant Andreu del Palomar (1881, with Pere Falqués), Teatre Poliorama and Reial Acadèmia de les Ciències (1883), Palau de la Justícia - Palace of Justice courthouse (1887-1908, with Enric Sagnier i Villavecchia), Palau Montaner, now the Delegación del Gobierno Español (Delegation of the Spanish Government) in Barcelona (1889-1896, with Lluís Domènech i Montaner), the University of Barcelona's Faculty of Medicine (1904), Modelo prison (1904, with Salvador Vinyals i Sabaté), the Amparo de Santa Lucía / Empar de Santa Llúcia home for the blind, which eventually became the Museu de la Ciència de Barcelona, now known as CosmoCaixa Barcelona (1904-1909), the Fabra Observatory (1906), Catalana de Gas i electricitat building and water tower (1908), the Church of Our Lady of Carmen (Església de la Mare de Déu del Carme) and Carmelite convent (1910-1921, finished by his son Josep Domènech i Mansana) and Magoria station (1912). He also headed the construction of the Hospital Clínic (1895-1906), based on a design by Ignasi C. Bartrolí (1881). In the town of Viladrau, he built the Hotel Bofill (1898).
Knowledge 1: Layana
Layana is a municipality located in the province of Zaragoza, Aragon, Spain. According to the 2004 census (INE), the municipality has a population of 120 inhabitants. [SEP] Knowledge 2: Martin of Aragon
Martin the Humane (29 July 1356 – 31 May 1410), also called the Elder and the Ecclesiastic, was King of Aragon, Valencia, Sardinia and Corsica and Count of Barcelona from 1396 and King of Sicily from 1409 (as Martin II). He failed to secure the accession of his illegitimate grandson, Frederic, Count of Luna, and with him the rule of the House of Barcelona came to an end. [SEP] Knowledge 3: Gothic architecture
The Palais des Papes in Avignon is the best complete large royal palace, alongside the Royal palace of Olite, built during the 13th and 14th centuries for the kings of Navarre. The Malbork Castle built for the master of the Teutonic order is an example of Brick Gothic architecture. Partial survivals of former royal residences include the Doge's Palace of Venice, the Palau de la Generalitat in Barcelona, built in the 15th century for the kings of Aragon, or the famous Conciergerie, former palace of the kings of France, in Paris.

Answer: built in the 15th century