The tank was first used in the final phase of the battle of the Somme. At first the attack made good progress, but the tanks were of limited effectiveness as they were few in number and somewhat unreliable.
Citation:
Editors. "British first use tanks on Western Front".
The Literary Encyclopedia. First published 01 March 2010
[http://www.litencyc.com/php/stopics.php?rec=true&UID=12410, accessed 23 May 2013.]