Phra Phutthayotfa Chulalok Maharaj (Thai: , 20 March 1737 7 September 1809), personal name Thongduang (), also known as Rama I, was the founder of the Rattanakosin Kingdom and the first monarch of the reigning Chakri dynasty of Siam (now Thailand). His full title in Thai is Phra Bat Somdet Phra Paramoruracha Mahachakkriborommanat Phra Phutthayotfa Chulalok ( ). He ascended the throne in 1782, following the deposition of King Taksin of Thonburi. He was also celebrated as the founder of Rattanakosin (now Bangkok) as the new capital of the reunited kingdom.

Rama I was born from a Mon male line descent family, great grandson of Kosa Pan. His father served in the royal court of the Ayutthaya Kingdom, and had served King Taksin in wars against the Burmese Konbaung dynasty and helped him in the reunification of Siam. During this time he emerged as Siam's most powerful military leader. Thongduang was the first Somdet Chao Phraya, the highest rank the nobility could attain, equaled to that of royalty. In 1782, he took control of Siam and crowned himself as the monarch. The most famous event in his reign was the BurmeseSiamese War of 178586, which was the last major Burmese assault on Siam.

The Grand Palace (Thai: พระบรมมหาราชวัง, RTGS: Phra Borom Maha Ratcha Wang) is a complex of buildings at the heart of Bangkok, Thailand. The palace has been the official residence of the Kings of Siam (and later Thailand) since 1782. The king, his court, and his royal government were based on the grounds of the palace until 1925. King Bhumibol Adulyadej (Rama IX), resided at the Chitralada Royal Villa and his successor King Vajiralongkorn (Rama X) at the Amphorn Sathan Residential Hall, both in the Dusit Palace, but the Grand Palace is still used for official events. Several royal ceremonies and state functions are held within the walls of the palace every year. The palace is one of the most popular tourist attractions in Thailand.

Construction of the palace began on 6 May 1782, at the order of King Phutthayotfa Chulalok (Rama I), the founder of the Chakri Dynasty, when he moved the capital city from Thonburi to Bangkok. Throughout successive reigns, many new buildings and structures were added, especially during the reign of King Chulalongkorn (Rama V). By 1925, the king, the Royal Family and the government were no longer permanently settled at the palace, and had moved to other residences. After the abolition of absolute monarchy in 1932, all government agencies completely moved out of the palace.

In shape, the palace complex is roughly rectangular and has a combined area of 218,400 square metres (2,351,000 sq ft), surrounded by four walls. It is situated on the banks of the Chao Phraya River at the heart of the Rattanakosin Island, today in the Phra Nakhon District. The Grand Palace is bordered by Sanam Luang and Na Phra Lan Road to the north, Maharaj Road to the west, Sanam Chai Road to the east and Thai Wang Road to the south.

Rather than being a single structure, the Grand Palace is made up of numerous buildings, halls, pavilions set around open lawns, gardens and courtyards. Its asymmetry and eclectic styles are due to its organic development, with additions and rebuilding being made by successive reigning kings over 200 years of history. It is divided into several quarters: the Temple of the Emerald Buddha; the Outer Court, with many public buildings; the Middle Court, including the Phra Maha Monthien Buildings, the Phra Maha Prasat Buildings and the Chakri Maha Prasat Buildings; the Inner Court and the Siwalai Gardens quarter. The Grand Palace is currently partially open to the public as a museum, but it remains a working palace, with several royal offices still situated inside.