The Excelsior was developed after early combat experience with Churchill infantry tanks. These tanks had very poor reliability and were also very slow for the modern battlefield. Thus, while the prototype A27 Cromwell was being developed, it was decided to use the A27 as a basis for a new universal tank meant to replace the cruiser and infantry tanks and combine them into a single vehicle. In 1942, the project was approved and the A33 Excelsior was born. However, the issues with the Churchill were fixed by 1943 and cruiser tanks were replaced by American M4 Shermans, thus the Excelsior was no longer needed and the project was cancelled.

It was introduced in Update 1.67 "Assault" as a reward for the 2017 "War Thunder Chronicles" event. The Excelsior is a weird tank, since it combines reliable armour, with good mobility and decent firepower for its BR. The gun is a 75 mm OQF Mk.V with good penetration values, although it lacks access to APHE shells like most British tanks of WWII, the gun handling is also great at -12 degrees of depression. The tank is also fairly survivable, especially if it is angled, and also has access to smoke launchers to easily retreat or change position. However the reverse speed is very poor and it should be taken into consideration, while the armour is decent, the Excelsior is a very large target and will easily be spotted from far away.