Complex sentence: St Roch, whose relics rest in the church, was declared a patron saint of the city in 1576 and every year, on his feast day (16 July), the Doge made a pilgrimage to the church.
Split into simpler sentences: St Roch, whose relics rest in the church, was declared a patron saint of the city in 1576. Every year, on his feast day (16 July), the Doge made a pilgrimage to the church.