Author Michael Bond, who created Paddington bear, has died at the age of 91.
His publisher HarperCollins said Mr Bond died at home following a short illness.
The English author, who grew up in Berkshire, wrote 150 books in total, with an additional 25 books about Paddington, who then came to life in a well-loved television series.
The official Paddington Twitter account posted a tribute to the late author, which was also retweeted by the official London Paddington Twitter page.
Mr Bond's first book, A Bear Called Paddington, was published in 1958 about the marmalade-loving bear from Peru.
HarperCollins chief executive Charlie Redmayne said: "Michael Bond was one of the great children's writers.
"At HarperCollins we are immensely fortunate to have published him and to have known him.
"He was a wonderful man and leaves behind one of the great literary legacies of our time."
The adventures of Paddington, who became a classic character in children's literature, came to the big screen in 2014, with a sequel scheduled to hit cinemas this year.
Ann-Janine Murtagh, HarperCollins executive publisher of children's books, told Sky News: "Michael Bond and his creation Paddington bear had so many things in common - a big heart, an infectious enthusiasm for life and a twinkle in the eye.
"Michael would have taken delight in everything that has gone on around Paddington because people loved Paddington, young and old."
Hugh Bonneville, who plays Mr Brown in the recent film adaptation of Paddington and its forthcoming sequel, said in a statement: "It seems particularly poignant that we should learn of dear Michael Bond's death on the last day of shooting our second film about his unique, loveable creation.
"In Paddington, Michael created a character whose enthusiasm and optimism has given pleasure to millions across the generations.
"Michael will be greatly missed by his legions of fans and especially by his wife Sue, his family and of course by his beloved guinea pigs. He leaves a special legacy: long live the bear from darkest Peru."
Mr Bond was awarded an OBE for services to children's literature in 1997, followed by a CBE in the Queen's Birthday Honours in 2015.