During the Battle of Lone Pine, Mr Keysor risked his life by picking up live Turkish grenades as they were thrown into the trenches and throwing them back.
Despite injury and an order to seek medical attention, Keysor continued to remain in the line, volunteering to throw bombs for another company.
Rabbi Major Reuben Livingstone, Principal Jewish Chaplain to HM Forces, said words of remembrance and prayers at the ceremony. The service was also attended by The Lord Mayor of Westminster, Councillor Christabel Flight, who unveiled the paving stone and past, present and future representatives from the Royal British Legion, HQ London District and Army Cadets.
The Victoria Cross is the highest and most prestigious honour bestowed on any serviceman who showed exceptional courage in the face of the enemy.
