This isn't a very good song, to anyone who knows the history. Purely from a factual point of view, the seige was certainly in 1791 not 1795, and the British were trying to get in, not out - what's more they were heavily outnumbered - Tipu had a relieving army but luckily was too scared to attack, and watched as Bangalore fell. Tipu's troops were well armed, trained and equipped (partly with French help)and were not equipped with 'only knives'. The seige was a dramatic affair - the British were operating at the end of very long suppy lines from Madras, always vulnerable to Tipu's excellent cavalry, and taking Bangalore was vital to them. Colonel Moorhouse, a hero of earlier battles against Tipu and his father was killed outside the walls (there's an excellent painting of this in the National Army Museum, London). As for the implication that it was the 'white man's fear of freedom' (sigh) that started the war, it was begun by Tipu's invading the territory of the Maharaja of Travancore, an ally of the British. Tipu was an extremely aggressive ruler, whose designs on the territory of his neighbors left those of the British, at that point at least, well behind. It was only the third in a series of four wars between them and the Mysore rulers, which finished when the British took Tipu's capital of Srirangapatna (Seringapatam) in 1799. Tipu was killed, fighting bravely, in the process.
As a final note, the lash was used on the back, not the face.