Known today as Ta Prohm or "Old Brahma", this monument was initially named "Rajavihara" meaning "royal monastery". In 1186 AD, Jayavarman VII consecrated several statues here, the most important of which was that of Prajnaparamita, the personification of the Perfection of Wisdom, a figure whom the King identified with his mother.
Reflecting without doubt a religious ideology, it is only some years later that the King dedicated another temple, Preah Khan, to his father whom he identified with Lokesvara. On an official level, this is clearly in the religious context of Buddhism of the Great Vehicle and, more specifically, in the context of a Khmer Buddhist context characteristic to Jayavarman VII's reign. However, one must be wary of too quick a judgement.
The word vihara in its original use, for example, should not be understood with the Theravadin eye of the modern era. On the other hand, all things considered, the one kilometer by seven hundred meters area delimited by the exterior enclosing wall can perhaps be regarded somewhat as a Vat (the modern Buddhist monastery).
Within the walls, many people of diverse capacities made up a cult. Ordinarily, the visitor enters the monument from the west to approach the heart of the complex. However, one must not forget that the ritual entrance was to the east.