Now the central building of the National Museum, the Front Palace used to be an enormous complex stretching from the Chao Phraya River across Sanam Luang to Lot Canal. It was built in the 18th-century, along with the Grand Palace. The Front Palace housed the heir to the throne, who was appointed by the King, usually a son or brother of the reigning monarch who bare the title Second King or Vice-King. The title of Second King started in the Ayutthaya Period, but gained a significant amount of power during the Rattanakosin Period when the Second King even got its own private army and navy. This large amount of power often led to conflicts between the King and the Second King. The last to bare the title of Second King was Prince Vichaichan. In 1884, he got into a power struggle with King Rama V in an event known as the Front Palace crisis. King Rama V tried to modernise Siam in a rapid pace, and conservative forces and the nobility, including Prince Vichaichan, saw their power and influence being slowly eroded. When Prince Vichaichan got a letter threatening his life, he mobilised up to 600 of his private troops around his palace. The King also mobilised his troops, but this only underlined that the Second King’s guards were more numerous and better equipped. After an explosion, a mysterious fire broke out in the Grand Palace, threatening Wat Phra Kaeo, and the Second King’s troops got on their way to the Grand Palace to try and extinguish it, however this was blocked by the King’s Royal Guards who feared that the fire was orchestrated by the Second King to take over the country. Afterwards King Rama V criticised the Second King for not moving all his troops to the Grand Palace, as an ancient custom dictated that the Second King’s troops must actively protect the King and the Grand Palace in an emergency. King Rama V ordered his troops to surround the Front Palace, and Prince Vichaichan fled to the British embassy. After mediation, the powerful Western countries supported King Rama V, who abolished the title and introduced the Western-style Crown Prince of Siam for the heir apparent. Prince Vichaichan died one year later. The palace was turned into the National Museum’s main building housing Thai art objects. Some walled remains of the old Front Palace complex can be found inside the Thammasat University complex.