As I understand it, tees used to actually be framed 'boxes' which held sand. Beside each tee box, would be placed a bucket of water. A golfer would scoop up a handful of sand, dip it into the water and form the combination into a little 'tee' which would hold the ball aloft until it was kerschmackled down the fairway.
I'm am not sure wether tee 'markers' were used at that time - but I doubt it, as I imagine the 'boxes' would not be large enough to warrant it - plus there was no grass to worry about regrowing.
At some point, grass tees became the norm, and tee markers came to be used to define the forward edge and width of a box which extends back two club lengths. This is the ground within which one is supposed to hit their tee shot from.
When and where did these markers come into being?