Short answers, pulled from the story.
Construction began in 1386 under Archbishop Antonio da Saluzzo, who appointed Simone da Orsenigo as the first chief engineer. Orsenigo planned a brick structure in Lombard Gothic style before political ambitions altered the course.
Napoleon Bonaparte ordered the façade completed in 1805 to ensure expenses fell to the French treasury even if reimbursement never arrived. This directive ensured the final details were finished by the 6th of January 1965 after nearly six centuries of work.
Saint Bartholomew Flayed stands at the left of the altar and is a statue created in 1562 by Marco d'Agrate. The sculpture shows the saint carrying his own flayed skin over his shoulders.
Astronomers at Brera Astronomical Observatory constructed a meridian line on the floor at the west end beginning on the 1st of December 1786 under Count Giuseppe Di Wilczek's direction. When sunlight crossed the brass line indicating solar noon, a signal alerted Sforzesco Castle to trigger a cannon fired across the city to synchronize all clocks.