I am cheating because this post isn’t linked to my British journey, even if it’s obviously linked to British Army. According to Wikipedia, 8 British heavy tanks were involved in the Second Battle of Gaza, between 17 and 19 April 1917.
The infantry were strengthened by a detachment of eight Mark I tanks along with 4,000 rounds of 4.5-inch gas shells. The tanks were deployed along the front to give shelter to the infantry advancing behind them, but as the tanks became targets the infantry also suffered. Two tanks succeeded in reaching their objectives. Although the gas shells were fired during the first 40 minutes of the bombardment on a woodland area it appears they were ineffective.