Jesus is sentenced to death by crucifixion. As part of the process of execution, he is first flayed without mercy. 

Mark 15:6-15 At festival time Pilate used to release a prisoner for them, any one they asked for. Now a man called Barabbas was then in prison with the rebels who had committed murder during the uprising. When the crowd went up and began to ask Pilate the customary favour, Pilate answered them, 'Do you want me to release for you the king of the Jews?' For he realised it was out of jealousy that the chief priests had handed Jesus over. The chief priests, however, had incited the crowd to demand that he should release Barabbas for them instead. Then Pilate spoke again, 'But in that case, what am I to do with the man you call king of the Jews?' They shouted back, 'Crucify him!' Pilate asked them, 'What harm has he done?' But they shouted all the louder, 'Crucify him!' So Pilate, anxious to placate the crowd, released Barabbas for them and, after having Jesus scourged, he handed him over to be crucified.

The Window

Christ's robes of red lie cast upon the floor, next to other instruments of torture. He stands tied to an upright pillar, while behind him a soldier raises high a many-tailed whip. Despite his abject suffering at the hands of men, the artist has chosen to place the heavenly castle at the top of the window, a reminder of the presence of God the Father above all the affairs of Earth.

The scroll in the bottom light reads Cuius livore sanatis estis  (for by His wounds you were healed).

The inscription at the foot of the window reads: This window was given by Julia and Jesse Humphreys in memory of their mother Jane Humphreys who died 21st December 1915. R.I.P. 

The Rosary
First Sorrowful Mystery
Third Sorrowful Mystery