great painting!!! but.....
there wasnt battle in tanneberg....in 1410 battle was in Grunwald... this is hard mistake : ) germans (teutonics)calls this battle tannenberg because they are to proud for akcept realy result of this big battle... tanneberg wasnt place of this batle...
The peg out of the breast plate is the rest for his lance when jousting and charging. I know there is a technical term for it but I evades my grasp at this time.