The elite units Grenadiers is a 16/17th century formalisation of infantry units that threw bombs/grenades. That was extra dangerous job as early bombs were not

The elite units Grenadiers is a 16/17th century formalisation of infantry units that threw bombs/grenades. That was extra dangerous job as early bombs were not reliable, and had a chance to explode too soon. But throwing a ball of metal with blackpowder is much older.