Well, this is a modification of the Boreas class battlecruisers.
About this creation
It is highly recommended that you check my DNS Boreas First, as this ship is using that as a basis.
So, backstory first:
January 1961: There are 6 of the 7 Boreas class Battlecruisers left in active service, with 1 being sunk in WW2. (bear in mind this is a fictional world but with a similar technological timeline).
It's February 1961, A shipboard vertical launch system is designed, it can carry 3 large ballistic missiles, or 12 smaller missiles. There is a requirement for a testbed for this brand new weapons system.
June 1961: There is a hangar explosion on the Skiron (The 6th of the 7 Boreas class vessels, launched early 1946). The explosion destroys the hangar and heavily damages the D turret and turret well. While the ship is undergoing repairs, the Domanian navy decides to use this opportunity to completely remove the aircraft hangar and D turret, to make way for 72 of the new VLS. A new helicopter hangar and helipad replace the C turret,The space saved from the ammunition of the aft turrets is now used to store more fuel oil and supplies, therefore increasing range. The amount of AA mounts were also reduced to 22* twin 40mm and 18* 20mm. The 127mm mounts were also reduced to 4* twin 127mm and 2* single 127mm. 2* rail based missile system now sit where the aft 127mm mounts used to be, each can launch 8 AA missiles, before being reloaded via and loading system in mounted in the side of the hull. The 40mm mounts on the side of the smokestack were also removed. Modern Radar was also incorporated. However, as a result of the new weapons systems the weight was increased.
After the modification, the classification was changed, The Skiron thus became the world's first Guided Missile Battlecruiser (CBG-1)
November 1963: The Skiron modification was so successful at bombardment and force projection, that the Domanian navy decided to convert 2 more Boreas class vessels, Kaikias & Zephyrus, into CBGs. These however were a little lighter than the Skiron, Because of better construction techniques.
Well, That's quite unlike me, having a backstory and all...