For many years Sir Tarquin held the Castle of Mamecestre against King Arthur and his Knights of the Round Table. On a tree outside the gates he hung the shields of his prisoners, together with a copper basin, which all who would challenge him must strike. But none could vanquish the haughty knight until Sir Lancelot de Lac resolved to put an end to Sir Tarquin's power, and release the threescore knights and four whom he held in prison. Sir Lancelot shattered the basin with a blow. Never again was it needed, for in a desperate combat Sir Lancelot finally overcame Sir Tarquin.