Marathon-Class

The Marathon-class Cruiser is a class of UNSC Navy warships. At 1,190 meters, they are some of the largest and most powerful warships ever utilized by humanity, built as a replacement for their aging Halcyon-class Cruisers. Their numbers were limited, and they were usually commanded by the highest ranking officers.

Description
These warships replaced the Halcyon-class Cruisers. These behemoths, at 1,190 meters, are slightly under three times the length of a UNSC Frigate. They are also known for their heavy armor; they can survive multiple plasma impacts and are able to sustain far greater damage than any UNSC Frigate or UNSC Destroyer. Due to their size, durability and firepower (2 MACs as well as dozens of oversized Archer missile pods), these massive vessels are commanded by UNSC Admirals and primarily serve as command/capital ships.

Use
Due to their diminishing numbers, and the onslaught of the genocidal Covenant, further numbers of these great cruisers have been reassigned to the defense of the Inner Colonies. They were considered extremely valuable in terms of firepower and armor, and it was seen to by the UNSC admiralty that they were only used in the most dire and occasional of circumstances. Marathons were present at the Battle of Sigma Octanus IV and the Fall of Reach. Twelve saw action at the Battle of Earth under Fleet Admiral Harper and another was part of Battle Group Stalingrad during the Battle of Onyx. It's likely that some were also engaged later battles.