The tallest person in recorded history

 Robert Pershing Wadlow(1918-1940) was an American man,the tallest person in recorded history for whom there is irrefutable evidence.

        His height was 8 feet 11 inches while his weight reached 199 kg at his death at age 22.His great size and his continued growth in adulthood were due to hypertrophy of his pituitary gland,which results in an abnormally high level of human growth hormone (HGH).