Setting: A version Medieval Europe where magic has always existed, but has evolved in a similar way to how technology changes, getting better with time. Eventually, someone figures out how to give a "sentience" to objects, given that the object meets some requirements.
Somewhere inside of the object there must be a magic core, which can be created by concentrating a moderate amount of magic into a rock (6 hours of channeling by a basic mage, less by more powerful ones for a rock equal to or less than a 1 foot by 1 foot by 1 foot cube. The spell does not work on bigger rocks).
The object must be able to move like a human, so it must have a body, 2 arms, 2 legs, and a head. These do not have to be detailed, but must still be connected. An easy way to do this is via short chains. If the chains are too long, or a part is too disproportional to the caster's body (magic uses this for reference), the spell will not work.
The golem's body can not exceed an 8 foot tall by 5 foot wide by 5 foot long box (if set up like a mannequin). It can exceed it via movement. It the body exceeds the box, the golem shuts off until it has been changed to fit the box. NOTE: More powerful mages can exceed the size I said, but I am trying to set this up around common people and not master grade mages.
Up-keeping a golem is not a task that has to be always done. But, while a golem is active under a person, that persons magic reserve maximum is dropped until the golem is either deactivated, or the core is destroyed. If the user does not have enough magic to upkeep the golem, but still tries, the person will go unconscious, and the core will be destroyed.
The golems (base ones) can carry as much as the material they are made of can handle. Any more, and they begin to crumble. Their speed is also dependent of the material, with heavier ones moving slower.
With the exception of combat, their AI has little to no intelligence (a more powerful mage can give one with more intelligence)(in combat, ordering it to attack will cause it to try and punch/bash whatever you order it to attack). The core though, links the minds of the creator and the golem. This allows for some level of control over the golem, besides voice commands. When not taking orders, they stand still like a statue. They are easy to notice while active though, seeing that the core, along with any links linking body parts together, and a dot on the face will all be glowing a random hue (stronger mages can set this hue).
The basic person has the energy to have 0-2 golems active at a time.
A golem can not be created of organic matter (the body parts), but can be garnished with it, like wood details or a flower laurel.
So, how would Medieval Europe change with the discovery of the ability to make golems?