Original: The present chapel , on the site of the Cappella Maggiore , was designed by Baccio Pontelli for Pope Sixtus IV , for whom it is named , and built under the supervision of Giovannino de Dolci between 1473 and 1481 .
Simplified: The Chapel was built between 1473 and 1481 by Giovanni dei Dolci for Pope Sixtus IV .