I would check the Wikipedia articles on Major Bruce Cameron and the Battle of Tsaritsyn.

In June 1919 the above Scottish officer and a handful of other British troops had been sent to Denikin's White army near Tsaritsyn to train them in the use of British tanks supplied to them. Despairing of the Russians slow progress in learning how to operate the tanks, Cameron decided to show them how it was done and ordered the handful of British troops to take one of the tanks and attack Tsaritsyn themselves. Totally surprised, the Red troops panicked and fled or surrendered, allowing this tiny British force to capture the city and turn it over to Denikins White Russians

Tsaritsyn was later renamed Stalingrad, in honour of Joseph Stalin who was one of the defending Red commanders. Thus, Britain succeeded in capturing Stalingrad where the Germans later failed.

I would check the Wikipedia articles on Major Bruce Cameron and the Battle of Tsaritsyn.

In June 1919 the above Scottish officer and a handful of other British troops had been sent to Denikin's White army near Tsaritsyn to train them in the use of British tanks supplied to them. Despairing of the Russians slow progress in learning how to operate the tanks, Cameron decided to show them how it was done and ordered the handful of British troops to take one of the tanks and attack Tsaritsyn themselves. Totally surprised, the Red troops panicked and fled or surrendered, allowing this tiny British force to capture the city and turn it over to Denikins White Russians

Tsaritsyn was later renamed Stalingrad, in honour of Joseph Stalin who was one of the defending Red commanders. Thus, Britain succeeded in capturing Stalingrad where the Germans later failed.