Note: I purposly left of the second part of this phrase in the node title because I wanted to avoid the armor / armour discussion.
Maximillian armour was best thing to happen to body armor in 300 years.
Really, I'm not kidding.
This is because Maximillian was the last last version of heavy body armour from the time it was introduced in the late 16th century until the early 1900's.
The Emperor Maximillian is responsible for the conception of this type or armour for two reasons; a) it was more fashionable than the blocky gothic armour or previous times, and b) it offered better protection against that most deadly of inventions, the musket.
Soldiers covered in plate armour were still the only game in towne in the early- to mid-16th century because the weapon of choice was really still the sword. But when the hand-cannon and the musket began to make their apperance it was found that ordinary plate armour did little to stop a lead ball travelling at super-sonic speeds.
Enter Maximillian armour: It's surface was textured in a way that was supposedly engineered to better deflect the blow of a musket ball and hopfully make it ricochet instead of puncture. It was also was usually much thicker and better tempered than armours that were designed to stop a blade. In fact, some suits of Maximillian armour were so heavy (some said to be in excess of 60 kilograms) they would cause permanent skeletal deformations in the wearer, and if they were to loose their balance, they would require a crane or battery of squires to right them again.
The sad truth is that, alought it was better than it's predecessors, bullet and gun technology was progressing too rapidly for heavy body armour to keep up with and by the time riflemen came around, a keen marksman could deliver a slug with such deadly accuracy that no personal armour of the day could stop it.
Maximillian armour is primarily characterized by armets and close helmets with bellows visors; small fan-shaped fluting often covering most of the harness (but never the greaves), and or course the ribbed treatment of the metal.
There are some very good pictures (if you're so inclined) at: