366 poems addressed to Laura, the woman Petrarch loved at a distance for decades. The collection invented the sonnet sequence and defined romantic love poetry for five centuries. The "Petrarchan" conventions (the unattainable beloved, the suffering lover, the paradoxes of desire) saturated Shakespeare, Sidney, and Spenser. The form is his gift; the obsession beneath the form is his genius.

The case for it, the case against, and the rest of the canon open with Pro.