'The King turned to the tables, and held him out his own cup of wine. The old man drank, and beckoned behind him, and, before all the Normans, my Hugh bore away the empty cup, Saxon-fashion, upon the knee.
This is from "The Tree of Justice" in Rewards and Fairies by Kipling.
I do not understand the meaning of below.
bear away the empty cup on the knee
Because the old man and Hugh are both standing.
I am so glad if somebody kindly teach me.