Short answers, pulled from the story.
John Gower was an English poet born around 1330 and died in October 1408, a personal friend of Geoffrey Chaucer and a contemporary of William Langland. He wrote three major long poems in French, Latin, and English respectively, and was regarded in the sixteenth century alongside Chaucer as a father of English poetry.
Gower's three major works are the Mirour de l'Omme (written in French, also known as the Speculum Meditantis), the Vox Clamantis (in Latin), and the Confessio Amantis (in English). Each poem is roughly thirty thousand lines long, and scholars have described them as forming a unified trilogy covering individual virtue, legal justice, and royal responsibility.
Gower and Chaucer were close friends and mutual influences. When Chaucer traveled to Italy on a diplomatic mission in 1378, he gave Gower power of attorney over his English affairs. Chaucer dedicated his Troilus and Criseyde in part to "moral Gower," and Gower placed a speech praising Chaucer in the mouth of Venus at the end of the first version of the Confessio Amantis.
Around 1385, King Richard II chanced to meet Gower on the Thames and invited him aboard the royal barge. Their conversation resulted in a royal commission that became the Confessio Amantis, a thirty-thousand-line poem in octosyllabic English couplets using the framework of a Christian confession.
Two passages in Gower's works have been identified as predictions of the Peasants' Revolt. One appears in the Mirour de l'Omme, using the metaphor of the stinging nettle to warn of an impending catastrophe, and the second is the closing couplet of Book Five, Chapter Ten of the Vox Clamantis. Gower's warnings were ignored both before and after the events of 1381.
In the eighteenth and nineteenth centuries, critics found Gower's work overly didactic and dull, and his closeness to the Lancastrian regime was seen as servility. The American poet James Russell Lowell famously claimed Gower had raised tediousness to the precision of science. His reputation began to recover after Macaulay published a complete edition of his works in 1901.