Maundy Thursday is the commemoration of the last supper, on the night Jesus was betrayed.

And He took the bread, gave thanks and broke it, and gave it to them, saying, “This is My body, given for you; do this in remembrance of Me.” In the same way, after supper He took the cup, saying, “This cup is the new covenant in My blood, which is poured out for you. - Luke 22:19-20