The history and culture of Ayutthaya can be divided into three main period :
The Early Ayutthaya Period, the Middle Period, and the Late Ayutthaya Period.
From an architectural viewpoint, we can make simple distinction between the three periods. During the first period, the Prang (adapted from Khmer architecture) was the most prominent structure within the temple compound. During the middle period, the chedi (or stupa), often in Sri Lankan (rounded) style became the most visible monument. During the later Ayutthaya period, the Ubosoth or Coronation Hall became larger and larger, and while the prangs and chedis are still there, they are less prominent.
Please bear in mind, that quite a few of the older temples have been restored. Therefore elements of newer architecture may be seen in the older temple compounds.