Sword & Silence

Those two dramas cover the same historical figures Queen SeonDeok, King MunMu of Silla, Kim Ch’unCh’u, Kim MunHui…famous characters during Korean 3 kingdom era.
Those two stories are connected as they follow each other within Korean early history. And cover some battles between them.
Great Queen Seondeok focused on the throne accession of Princess Seon Deok.
Sword & Silence is dedicated to King Munmu of Silla which is Kim Ch’inCh’u and Queen Munmyeong’s son and it seems like (drama isn’t aired yet) up to unification to create Goryeo. Ch’inCh’u was one the characters we can discover during his early years mid-way in the Great Queen Seondeok, a young Prince that was willing to take over the Silla throne after his Grandfather.
Both dramas are heavy on battles and politics.
One is a MBC old classics centered around Queen Seondeok access to the throne and opposition with the unfamous Misil, the other is a new take where the male characters have the centered stage.

Two period dramas taking place during Korean 3 kingdom era. Hwarang covering a prior time at Silla kingdom. The Hwarangs were sillian soldiers trained for all the battles that opposed these 3 kingdoms that ended reunited to create Goryeo.

Korea Khitan War was the previous historical drama made by KBS about war time in 2023. It covered a famous war during Goryeo that Goryeo lost to Khitans.
Sword & Silence covers also a Korean War time but during 3 Kingdom era.
Nowadays Korean sageuks are shorter than they used to 10 years ago, those 2 dramas are 32 and 28 episodes, from the same channel and aired at the same weekly time slot.