Middle Khmer is the historical stage of the Khmer language as it existed between the 14th and 18th centuries, spanning the period between Old Khmer and the modern language. The beginning of the Middle Khmer period roughly coincides with the fall of the Angkorian Khmer Empire to the Siamese Ayutthaya Kingdom and the period of Cambodian history popularly referred to as the Dark ages of Cambodia. The Middle Khmer period was a stage of transition which saw relatively rapid and dramatic changes, especially in phonology, that ended with the emergence of a language recognizable as Modern Khmer approximately concurrent with the 1777 coronation of Ang Eng, the father of the poet-king Ang Duong.