He got a job in London as a postal clerk. He struggled to pay his bills, he had a series of unhappy love affairs, and nothing came of his writing. Then, in 1841, he was offered a transfer to Ireland, and he saw it as a chance to make a clean start.
In Ireland, Trollope developed a social life for the first time. He went hunting, and he went to pubs and he fell in love and got married, all within a few years. Once he had settled down to his new life, he began to write fiction. In his job for the postal service, he rode a horse over all the rural routes himself, to ensure that a letter could be delivered to the remotest possible areas. It was while he was riding across the countryside that a fictional English county called Barsetshire sprang up in his mind.
In just eleven years, between 1855 and 1866, Trollope published six novels about the extended families and parishioners and civil service workers living in that imaginary county of Barsetshire, novels such as The Warden (1955), Barchester Towers (1857), and The Last Chronicle of Barset (1866), all of which were best-sellers.
The novelist Henry James said, "Trollope did not write for posterity. He wrote for the day, the moment; but these are just the writers whom posterity is apt to put into its pocket."
Anthony Trollope said, "Of the needs a book has, the chief need is that it be readable."
http://writersalmanac.publicradio.org/programs/2006/04/24/index.html