عبد الملك بن مروان
According to Islam Question and Answer website, points/dots to distinguish consonants were added to the Quran during the era of Caliph Abd al-Malik ibn Marwan, by the "knowledgeable, righteous, pious" scholars Nasr ibn ‘Aasim al-Laythi and Yahya ibn Ya’mar al-‘Adwaani.