The invasion and overthrow of Egypt by the Hyksos (c.1660-1550 BC) was due to superior military techniques and strategies. The Hyksos were already masters of mobile warfare with the advent of the horse drawn chariot, a formidable fighting machine, which the Egyptians had no answer to until they introduced their own version of the war chariot at the beginning of the 18th dynasty (c.1550-1295 BC). ...The Egyptians were not the inventors of the war chariot - this honour can be attributed to the Syrians. In fact, the first time the Egyptians saw a chariot was during the war against the Hyksos (c.1650-1550BC). The first known inscription depicting an Egyptian chariot is to be found on a scarab belonging to Thutmosis I c.1524-1518 BC pursuing a foe.

[http://www.egyptologyonline.com/the_army_in_ancient_egypt.htm]