Gun tankers had been used in warfare since the 13th century. The Chinese had used them to defend themselves against Mongol invaders, the Mughals frequently used them on the battlefield and the Europeans had started experimenting with them by the 15th century.
However, these gun tankers were built with flimsy materials like cardboard and were not very effective in inflicting damage on the enemy, similar to modern-day firecrackers. Thus, their use as a weapon had been discarded in favour of cannons and other forms of artillery.
It was the de facto ruler of 18th century Mysore, Hyder Ali, who developed the first prototypes of sturdier explosives-filled rockets. His innovation was further fine-tuned by his son Tipu who planned, designed and crafted cylindrical iron tubes that would allow for great compression of the filled gunpowder and consequently, greater range (nearly 2 km).