Originally built in 1565 by King Setthathirat to house the Emerald Buddha and to be his personal place of worship, Ho Phra Keo never had any monks residing in it. The Emerald Buddha itself was carried off by the Siamese in 1779 and placed in the Bangkok temple of the same name. Ho Phra Keo was reduced to rubble during the Siamese invasion of 1828 and remained in that state until 1937, when Uparat (Viceroy) Prince Phetsarath, impressed by the restoration work undertaken by the French authorities at Wat Sisakhet (1927-1931) and Phra That Luang (1930-1935), requested the colonial government to rebuild the monument. After several missions to Vientiane by Henri Marchal, who was known for his restoration work at Angkor, work commenced in 1937 under the direction of Prince Phetsarath's younger brother Prince Souvanna Phouma (1901-1984), who had just returned from studying public works engineering in France. The reconstruction work was funded jointly by the École Française d’extrême-orient (EFEO) and Vientiane Municipality, and after extensive research into the original design the monument was rebuilt using modern methods and materials. It is said that the reconstruction was based closely on the original plan, although this is disputed since the architecture of the present structure is more representative of 19th-century Bangkok style. The reconstruction took five years and on 18 March 1942, in the presence of Prince Phetsarath and Admiral Découx, Governor General of Indochina, Ho Phra Keo was solemnly reinaugurated, becoming a focal point of the Samay Funfou Xat (National Renovation) movement, which sought to develop a sense of Lao nationhood in order to counter Siamese efforts to unite all Tai-speaking peoples under a 'Greater Siam'. Having amassed a large and important collection of religious artefacts since 1917, Prince Phetsarath now decided to house these in Ho Phra Keo, seeking to establish the wat as a museum of religious art for the capital. During the Japanese occupation of 1945 this collection was moved for safe keeping to the Musée Louis Finot in Hà Nội, but it returned to Ho Phra Keo in the mid 1950s. Unfortunately, in the absence of funds or expertise to develop the collection, the wat remained a locked store-room until 1968 when, on the request of the Lao government, Madeleine Giteau of the Ecole Française d'extrême-orient came to Vientiane to reorganise the collection and improve its display, finally allowing the museum to open its doors later that year. Ho Phra Keo was designated as a National Museum in 1975.