Tudhaliya was likely born in his father's court in Hattusa, after his brother and crown prince Nerikkaili, but still while their father was governing on his brother Muwatalli II's behalf. He was a good friend of Muwatalli's son, Kurunta, and Hattusili ordered that they stay on good terms.
After Hattusili as King wrote up a treaty with "Ulmi-Tessup" which confirmed Kurunta's rule over Tarhuntassa, Hattusili elevated Tudhaliya over his older brother to be his crown prince. Tudhaliya as king drew up a bronze tablet treaty confirming the links between him and Kurunta. During his reign, 13 dams were built after a severe drought, one of which still survives to this day at Alacahöyük.