Changes

This pattern was issued after the introduction of the [[Mk IV|Mk IV Maximus-pattern power armour]]{{Fn|37a}} to the veterans of a [[Chapter]]'s [[1st Company]] and is possibly considered the most advanced form of Tactical Dreadnought Armour, and was said to be a technological masterwork.{{Fn|25}} It shared many systems with the Mk.IV, whilst providing greater mobility for the wearer compared to the later Indomitus Pattern with no loss in durability.{{Fn|4}} The Tartaros pattern armour is strong enough to withstand blasts a hundred times more powerful than one produced by an Astartes [[frag grenade]].{{Fn|28}} It was also known to weigh several tonnes,{{Fn|24}} yet is still more lightweight in comparison to other, more common Terminator armour patterns.{{Fn|28}} Tartaros armour is more streamlined and power efficient than its predecessors, making it more agile and providing short bursts of extra speed when needed, but was also more difficult and resource intensive to manufacture.{{Fn|25}}

This pattern was mostly used during the last decades of the [[Great Crusade]] and during the [[Horus Heresy]], and had become one of the most widely-circulated patterns issued.{{Fn|25}} In [[M41]] suits of Tartaros Armour are incredibly rare. Even so some of the Space Marine Chapters have suits in their possession and still deploy these venerable relics, giving them to the most able members of the 1st Company.{{Fn|17}}{{Fn|4}}