Which poet first popularized the sonnet form?1

The sonnet, a 14-line poetic form, owes much of its popularity and development to the contributions of the Italian poet Petrarch. Francesco Petrarca, commonly known as Petrarch (1304-1374), was a prominent figure of the Italian Renaissance and is often referred to as the "Father of Humanism." While he excelled in various forms of poetry, his influence on the sonnet is particularly noteworthy.
Petrarch's collection of poems titled "Canzoniere" or "Rerum vulgarium fragmenta" (Fragments of Vernacular Matters) is considered one of his most significant works. This collection consisted of 366 poems, many of which were sonnets. Written in vernacular Italian, these sonnets explored themes of love, beauty, and the complexities of human emotion.
Petrarch's sonnets are renowned for their structure, language, and thematic depth. He typically employed the Petrarchan or Italian sonnet form, which consists of an octave (eight lines) followed by a sestet (six lines). The octave often presents a problem or a situation, while the sestet offers a resolution, a counterargument, or an emotional response to the situation presented in the octave. This structure allowed for a nuanced exploration of ideas within a confined space.
The themes of Petrarch's sonnets often revolved around his unrequited love for Laura, a woman he supposedly encountered in Avignon, France. Laura became his muse and a source of inspiration for his poetry. Petrarch's portrayal of his intense emotions, combined with his skillful manipulation of language, imagery, and rhyme, created a powerful emotional impact that resonated with readers.
Petrarch's influence extended far beyond his native Italy. His sonnets were widely read and admired throughout Europe. As his poems were translated into different languages, including English, his style and form began to shape the works of poets from various regions. One of the most famous English poets who adopted the sonnet form was William Shakespeare, who popularized the Shakespearean or English sonnet. Shakespeare's sonnets, written around the late 16th century, further elevated the sonnet's status in English literature.
Petrarch's legacy as the pioneer of the sonnet form persists to this day. His ability to capture complex emotions, explore universal themes, and create a harmonious blend of form and content made his sonnets timeless. They paved the way for future poets to experiment with the structure and use the sonnet to convey a wide range of emotions and ideas. The sonnet's enduring popularity can be traced back to Petrarch's masterful contributions, making him a pivotal figure in the evolution of poetic expression.