Leonardo was born on April 15 , 1452 ( Old Style ) , `` at the third hour of the night '' in the Tuscan hill town of Vinci , in the lower valley of the Arno River in the territory of the Medici-ruled Republic of Florence .
Leonardo was born on 15 April 1452 , in the Tuscan hill town of Vinci , in the valley of the Arno River .