The Crown Prince of Thailand is a title held by the heir apparent to the Thai throne. It was created by King Chulalongkorn in 1886, for his son Prince Maha Vajirunhis, the king's eldest son by a royal wife Queen Savang Vadhana. Prior to this, the Siamese throne did not have a law or formal system regulating royal succession. In 1688, King Phetracha of Ayutthaya created the title of Front Palace, which by the Rattanakosin period had become the main title granted to the heir presumptive to the throne. However, few Front Palaces succeeded to the throne this way, with the exception of King Phutthaloetla Naphalai in 1809. After the death of Bowon Wichaichan in 1885, the title of Front Palace was abolished and replaced with the title of Crown Prince, who became heir apparent to the throne.