When did composers start using dynamics?

Dynamics are markings in musical notation that indicate how loud or soft a passage of music should be played. They were first used in the 16th century by Italian composers such as Giovanni Gabrieli and Claudio Monteverdi. Dynamics were originally indicated by words such as "forte" (loud) and "piano" (soft), but later became more standardized with the use of symbols such as > (crescendo) and < (diminuendo).