SriRanganatha Srirangam andLord Srinivasa Tirumala Interconnected
Sriranganatha of Srirangam and Sri Venkateswara of Tirumala are one and the same - Lord Maha Vishnu.
When muslim rulers invaded the Southern states, the Srirangam Temple was shut and the processional dieities and Valuable ornaments of the Lord had been shifted to Tirumala for Safe Custody. Thus Sriranganatha happened to be in Tirumala Temple for a number of years. When the invasion threat abated, the dieties and ornaments were taken back to Srirangam. That is why the place SriRanganatha Occupied during his Sojourn in Tirumala is even today known as Ranga Mandapam.