Govinda III's father was Druva (Dhruva Dharavarsha) who was before Govinda III, the greatest of the Rashtrakutas. Even though he ruled for only 13 years, by the end of his reign, he had no one to challenge him from Kanyakumari to the Himalayas. Govinda III was his younger son who was preferred over the eldest, Stambha who Druva made a viceroy of Gangavadi. As could be expected, Stambha rebelled and with the help of the Pallava King & Sivamara , the Ganga crown prince (who was earlier magnanimously released by Govinda III) challenged Govinda III who after defeating him, reinstated him as viceroy and Stambha stayed loyal for the rest of his life. Sivamara was again imprisoned, the Pallava King Dantiga defeated. Vishnuvardhana IV of vengi who was the maternal grandfather of Govinda III acknowledged Rastrakuta supremacy as did the king of Nolambavadi who offered an unconditional surrender & was reinstated.
In N.India the Gurjara Pratihara king Nagabhata II had inflicted a crushing defeat on the Pala king Dharmapala & reclaimed Kanauj (Govinda III's father Druva had defeated both Nagabhata's father Vatsaraja and Dharmapala who did take back Kanauj after Druva went back since the Rashtrakutas were after glory & not territory) Nagabhata II was at the height of his glory when Govinda III marched against him. He placed his loyal brother Indra (who he had earlier entrusted the kingdom with while putting down the rebellion of his elder brother Sthamba) in charge of keeping watch over the Vindhyan passes to pre-empt any invasion by Nagabhata into the Deccan and keeping sufficient detachments in Central India to preserve his lines of communication, he marched into Northern India probably through Bhopal & Jhansi. In the ensuing battle, the Rashtrakuta army of Govinda III crushed the Gurjara Pratihara army of Nagabhata forcing Nagabhata to flee the battlefield. The puppet emperor of Kanauj, Chakrayudha immediately offered unconditional surrender to Govinda III as did his master Dharmapala who had absolutely no interest in challenging the Rashtrakuta might since he figured that like his father Druva, Govinda III would not stick around in North India & would return home leaving Dharmapala the ruler of most of North India with the Pratihara challenge shattered. That was pretty much how it worked out & Dharmapala was the major benificiary of Govinda III's northern expedition. For Govinda III, the northern campaign was primarily one of assertion of suzerainity, rather than formal annexation of territory. (he just went on a pilgrimage to Kashi, Prayag & Gaya)
With Govinda III engaged in N.India, the kings of S.India - Pallava, Pandya, Kerala & Ganga had united & invaded the Rastrakuta dominions. Govinda III marched swiftly against them & crushed the coalition and was especially severe on the Gangas, killing all the leaders of their army. He then marched into the Pallava capital Kanchi and then defeated the Keralas & Pandyas as well. The king of Ceylon who was probably thoroughly frightened by the events across the sea promptly offered Govinda III his submission & sought friendship.The eastern Chalakya ruler of Vengi, Vijayaditya II who had also risen against the Rashtrakutas was deposed & his brother Bhima put on the throne. That pretty much ended any & all challenges to Govinda III & the last 5 years of his rule passed without any battles because there was none in the whole of India to challenge his authority.