As noted in the preceding gallery ("The Royal Barges"), Thailand's majestic procession of royal barges has antecedents dating from the Ayutthaya period and the reign of Narai the Great in the latter half of the 17th century. The processions have rarely been performed in recent years; in fact, there have been only 16 such performances over the past 80 years. The procession traditionally has marked the end of the annual Buddhist retreat during the rainy season, as the king and members of the royal family bring new robes to the monks at monasteries along the Chao Phraya River in a ritual known as the Kathin Ceremony.