The existing structure was started on the orders of Manuel I (1515-1520) to commemorate Vasco da Gama's successful return from India. It was originally meant as a church for the burial of the House of Aviz, but it also became a house of prayer for seamen leaving or entering port. Construction of the monastery began in 1502 and took 50 years to complete. He used pedra lioz, a local gold-coloured limestone, for its construction. The building of the monastery was funded by a 5% tax on eastern spices, with the exceptions of pepper, cinnamon and cloves, revenue from which went straight to the Crown. By this influx of riches, the architects had enough financial margin to think big. The enormous amount of funds needed for this monastery, meant abandoning the construction of the Aviz pantheon in the Monastery of Batalha. The monastery was designed in the Manueline style by Diogo de Boitaca (who was probably one of the originators of this style with the Igreja de Jesus in Setúbal). He built the church, the monastery, the sacristy and the refectory. He was succeeded by the Spaniard João de Castilho, who took charge of construction in around 1517. João de Castilho gradually moved from the Manueline style to the Plateresco style, a style with lavish decorations that remind of silver ware (plata = silver). There were several sculptors who made their mark on this building. Nicolau Chanterene added depth with his Renaissance themes. The construction came to a halt when the king Manuel I died in 1520. The architect Diogo de Torralva resumed the construction of the monastery in 1550, adding the main chapel, the choir and completing the two storeys of the monastery, using only Renaissance motifs. His work was continued in 1571 by Jérôme de Rouen (also called Jerónimo de Ruão) who added some Classical elements. The construction stopped in 1580 with the union of Spain and Portugal, because the building of the Escorial in Spain was now draining away all the funds. The monastery withstood the Great Earthquake of 1755 without too much damage. But when the building became vacant in 1833 by the abolition of the religious orders in Portugal, it began to deteriorate to the point of almost collapsing. A cupola was later added to the southwestern tower. On December 13, 2007 the Treaty of Lisbon has been signed at the monastery, laying down the basis for the reform of the European Union.