Wideok sent an immediate congratulatory mission to the Sui court in 581, and another in 582. In 589 Sui conquered Chen and united China. In the same year, a Sui warship happened to run aground on Jeju Island, which was ruled by the Baekje dependency of Tamna. Wideok provided the crew with an official escort (bearing tribute and congratulations) to the Chinese court. In 598 he sent an embassy offering to assist in the Sui expedition against Goguryeo that year. The expedition, however, had already been completed. Yeongyang of Goguryeo launched punitive attacks on Baekje's northern border when he learned of this.