The tank trials held at Hatfield Park were vital to the war effort. The first one took place on 29th January 1916 and the second one a few days later on 2nd February. A couple of days after this a private demonstration of the trials was organised for the King, Lord Kitchener and David Lloyd George.
A mock battlefield had been laid out with trenches and shell holes of various sizes.
Following these trials, the tanks took part in the Battle of the Somme.