Judging from the reports in the Samguk Sagi, Adalla's reign was a time of considerable expansion. Because Silla was still a small state, however, some scholars doubt the chronology, or attribute the territorial battles with the Seok clan, who replaced the Bak clan as Silla royalty after Adalla's reign.
He is said to have opened the road over Haneuljae (in present-day Mungyeong) in 157, and also the pass of Jungnyeong (in present-day Yeongju) in 159, extending Silla north of the Sobaek mountains.
Tensions increased with the rival Korean kingdom Baekje for harboring a Silla traitor. The Samguk Sagi reports 20,000 soldiers and 8,000 cavalry of Silla battled Baekje in 167.
During his reign, Adalla maintained peaceful relations with the Wa of Japan, who sent an envoy in 158. Himiko sent another envoy in 173.