Short answers, pulled from the story.
Gaetano Donizetti was born in 1797 and faced a throat defect known as difetto di gola that made him a poor choirboy during the first three months of trial at Simon Mayr's Lezioni Caritatevoli school. The school administrators were ready to dismiss him, yet Mayr saw something extraordinary in the child and convinced the school to keep him despite the physical limitation.
Gaetano Donizetti wrote over 70 operas between 1818 and 1848, with his first one-act opera being Il Pigmalione written when he was only 19. This work may never have been performed during his lifetime, yet it marked the beginning of a career that saw him produce works at a rate that baffled his contemporaries.
Anna Bolena was first performed at the Teatro Carcano in Milan on the 26th of December 1830 and achieved instant fame throughout Europe. This success solidified Gaetano Donizetti's reputation as a composer of successful serious opera and established him as the sole reigning genius of Italian opera following the death of Vincenzo Bellini and the retirement of Gioachino Rossini.
Gaetano Donizetti moved to Paris in 1838 to gain greater freedom to choose subject matter and receive larger fees and greater prestige. In Paris he wrote Les Martyrs, his first grand opera in the French tradition, and La fille du régiment, his first opera written specifically to a French libretto.
Gaetano Donizetti died on the afternoon of the 8th of April 1848 in Bergamo after a serious bout of apoplexy occurred on the 1st of April. He had been diagnosed with cerebro-spinal syphilis and severe mental illness in August 1845 and died in a state of mental derangement due to neurosyphilis.