A very thorough and readable history for the WW2 period: the work of the corps at home and overseas, and the impact of Partition. The maps, and detailed index, are exceptionally helpful.
The Indian Engineers were a part of every division in the army. The Engineers corps started the war with two army troops companies, 11 field companies and one field park company. Expansion during the war took the totals of Engineers to five army troops companies, 67 field companies, six independent field squadrons, 20 field park companies and two independent field park squadrons.
The Indian Army began the war, in 1939, numbering just under 200,000 men. By the end of the war it had become the largest volunteer army in history, rising to over 2.5 million men in August 1945. Serving in divisions of infantry, armour and a fledgling airborne force, they fought on three continents, in Africa, Europe and Asia. The Indian Army fought in Ethiopia against the Italian Army, in Egypt, Libya and Tunisia against both the Italian and German Army, and, after the Italian surrender, against the German Army in Italy. However, the bulk of the Indian Army was committed to fighting the Japanese Army, first during the British defeats in Malaya and the retreat from Burma to the Indian border; later, after resting and refitting for the victorious advance back into Burma, as part of the largest British Empire army ever formed.