Krishnadevaraya first attacked Udayagiri in 1512 A. D. He besieged the fort with his strong army. That fort was a great strong-hold of the Odishan army in the South. Being unable to make his entry into the fort, the emperor prepared new routes through stones and his army entered into the fort. The Udayagiri fort was captured at least in 1513 A.D. and Tirumala Routaraya, the uncle of Prataparudradeva was made captive. Krishnadevaraya, then focused his attention on the Kondavrdu fort which was another stronghold of Prataparudra in the South. Saluva Timma was appointed on behalf of Krishnadevaraya to carry on the operation. Saluva Timma besieged the fort of Kondavidu. The Amuktamalyada states that the Odia soldiers who were inside the fort of Kondavidu “went to heaven without any wounds in their bodies.” This fact has also been corroborated by the Mangalagiri pillar inscription. The narration of both the sources are indirect and an observation on it can be made in this way that being besieged by the soldiers of Krishnadevaraya, the Odia soldiers inside the fort of Kondavidu met their end by starvation and lack of water. This led to the fall of Kondavidu in 1515 A.D.
The Amaravati, Tiruvannamalai and Kalahasti inscriptions of Krishnadevaraya with the accounts of Nuniz provide with a list of important persons captured during the siege of the Kondavidu fort. Among them were Balachandra Mohapatra, Narahari Patra, Mallu Khan, Udanda Khan and last but not least, Virabhadra, the valiant son of Prataparudradeva. In the meanwhile, the forces of Krishnadevaraya also occupied other minor fortresses of the region like Addanki, Vinukonda, Bellamakonda, Nagarjuna Konda, Tangenda and Ketavaram. The next target of Krishnadevaraya was Kondapalli. This was the last attempt of the Odia soldiers to check the progress of Krishnadevaraya. Praharesvara Patra, the commandant of this fort, fought with the army of Vijayanagara Empire but was defeated. From the Kalahasti inscription, it isknown that from the side of the Odias Sirsachandra Mahapatra, Bijili Khan and Bodhan Mahapatra were taken as captives. Nuniz informs that during the capitulation of Kondapalli, a queen of Prataparudradeva was taken as a captive by krishnadevaraya which has been rejected by almost all the scholars in the absence of any other corroborative evidence. Of course, Prataparudra tried to check the progress of Krishnadevaraya but he was defeated repeatedly at the hands of the latter. Prataparudradeva proceeded back towards his capital Cuttack to assemble fresh army to deal with Krishnadevaraya.
Finding no opposition, Krishnadevaraya proceeded towards Odisha and reached Simhachalam. There he planted the pillar of victory. Though he sent news to prataparudra to meet him, the latter did not turn up. The Amuktama/yada and Manucharita inform that Krishnadevaraya proceeded to Puri, worshipped the Gods, marched towards Cuttack, burnt the capital and inflicted a crushing defeat upon the Gajapati of Odisha. Why Prataparudradeva did not turn up to fight against Krishnadevaraya. It was only because the death of his valiant son Virabhadra due to the disgrace (as Virabhadra was directed by Krishnadevaraya to display sword-fighting with a man who was not of noble birth) in the court of the Vijayanagara empire. This weakened the strength of his mind and conquering zeal and he had no alternative but to conclude peace with Krishnadevaraya by giving his own daughter Jagamohini (Tukka) to the latter. As a result of this peace treaty, river Krishna was marked as the line of demarcation between Vljayanagara empire and that of Prataparudradeva. Being weak in mind due to the death of Virabhadra and the miserable fate of his daughter, he found panacea in Vaisnavism and became an ardent follower of Sri Chaitanya. He breathed his last in 1540 A.D. His death paved the way for the downfall of medieval Odisha. Of course, Prataparudradeva had marched with his army to the Vijayanagara empire after the death of Krishnadevaraya in 1529 but sustained defeat at the hands of Achyutadeva and never marched again to that land till his death.