What is an analysis of the Matilde Urrutia sonnets?

Matilde Urrutia was the third wife of Pablo Neruda and the subject of a series of his work, mostly sonnets. The first work of Neruda's to reference Urrutia was Los Versos del Capitan. He would later dedicated much of his collection 100 Love Sonnets to Urrutia.
Before Neruda finalized his marriage with Urrutia, he began a passionate affair with her and even bought a property in Santiago, Chile to host their meet-ups. The sonnets that he dedicated to her were lush, vivid, and poetic in the typical Neruda style. Neruda, despite being known as a political Marxist poet in his country, was highly skilled in composing love poems. Some of his most famous poems come from 100 Love Sonnets.
In the poems dedicated to Urrutia, the reader can feel the intense love he had for her and that she served as a muse for his writing career until his death. The two were devoted to each other; so much so that Urrutia would edit his memoir after his death, despite opposition from the dictator, Augusto Pinochet, who labeled Neruda as a communist radical and tried to suppress his works.
The sonnets are reminiscent of Keats and Byron, illustrating the influence of the Romantics in Neruda's works. However, despite Neruda's feelings for Urrutia, he withheld the publication of his earlier works for her, particularly Los Versos del Capitan, out of respect for his wife.
While he did practice extramarital affairs, Neruda held the loves of his life in a high regard. His sonnets for Urrutia would go on to be considered some of the most beautiful love poems in the Spanish language.