The Parthasarathy Temple, also known as Arulmigu Parthasarathyswamy, is a Vaishanavite temple dedicated to Lord Krishna. Lord Krishna is in the form of ‘parthasarathy’, the charioteer for Arjuna in the Mahabharata war.
The temple is most widely renowned as one of the 108 sacred places where Lord Vishnu is worshipped. The temple is said to be unique as it has four different incarnations or forms of Lord Vishnu, namely, Lord Krishna, Lord Rama, Lord Narasimha and Lord Varaha.
Here all the four forms of Lord Vishnu can be worshipped at a single place, which further increases its importance among people making pilgrimages to holy places. This place has been identified in historical literature as well as sung about by innumerable fabled devotees of Lord Krishna like Thirumazhisai Alwar, Peyalwar and Thirumangaialwar. The temple stages a lot of festivals throughout the year in honour of different gods and this attracts a barrage of devoted worshippers from all parts of the country. They celebrate the festivals filled with rituals, songs, dances, pujas and delicious feasts.
Source : http://sriperumbudur.in/