[1] Historically, Nagamangala came into prominence during the rule of Hoysala King Vishnuvardhana when it became an important center of Vaishnava faith and received patronage from one of his queens, Bommaladevi.

[6][7] The temple is a large structure and has received patronage by multiple dynasties and reveals features of the later day Vijayanagara empire whose rulers added the entrance and tower over it (mahadvara) and bounding walls (prakara).

To the east, the large hall opens onto the platform that is meant for clockwise Circumambulation by devotees since the inside of the temple does not provide any such feature.

[4][10] On the platform, the base of the temple (called adhisthana) consists of moldings that take the stellate form of sanctum but become staggered square at the mahamantapa.

[2] The temple gets its name from the "serene" (lit, "Saumya") six feet tall image of Keshava, a form of the Hindu god Vishnu that stands on a garuda (eagle) pedestal.