The name suffix -vain appears in this and other Arthurian names such as Yvain and Agravain.
This name was popular throughout the English-speaking world in the early 20th century. It staged a comeback in the early 21st century, returning to the American top ten in 2017.
As an English name, Monica has been in general use since the 18th century. In America it reached the height of its popularity in the 1970s, declining since then. A famous bearer was the Yugoslavian tennis player Monica Seles (1973-).
The sonnets of William Shakespeare, on the other hand, are typically three Sicilian quatrains, followed by an heroic couplet.