Though illiterate, Hyder Ali earned an important place in the history of southern India for his administrative acumen and military skills. He concluded an alliance with the French, and used the services of French workmen in raising his artillery and arsenal. His rule of Mysore was characterised by frequent warfare with his neighbours and rebellion within his territories. This was not unusual for the time as much of the Indian subcontinent was then in turmoil. He left his eldest son, Tipu Sultan, an extensive kingdom bordered by the Krishna River in the north, the Eastern Ghats in the east and the Arabian Sea in the west.