The series follows the adventures of Thomas, an anthropomorphic blue steam locomotive on the fictional Island of Sodor along with his friends Edward, Henry, Gordon, James, Percy, Toby, as well as others.

The first episode (based on "The Sad Story of Henry") was broadcast live on the evening of Sunday 14 June 1953 from Lime Grove Studios.

[3][4][5] The live broadcast did not fare well: a failure to switch the points caused the model of Henry to derail and it had to be replaced on the rails by one of the operators.

In the end, after several years of searching and having to place a second mortgage on her home, Allcroft raised sufficient funding from her local bank manager.

The series started production in 1984, produced by Clearwater Features Ltd. (Mitton and Cardona's company) and ITV's Central Independent Television region.

[13] The story "Gordon Goes Foreign" from the Railway Series book The Eight Famous Engines was also planned to be adapted but was scrapped due to budgetary limitations.

[15] One of the primary reasons for diverging from the original books was that many of the stories not yet used featured large numbers of new characters, which would be expensive to produce.

Only one original story ("Rusty to the Rescue", written by Allcroft and Mitton) was used, the rest were all adapted from the Railway Series books, but this took certain elements of its plot and dialogue from Stepney the "Bluebell" Engine.

Despite high production values and the popularity of the show, the film was criticised by British reviewers who were unfamiliar with Shining Time Station.

[19][20] The sixth and seventh series (2002-2003) were first released directly to VHS and DVD as forty-six episodes in the US and fifty-two in the UK, and continued to introduce action-packed storylines, as well as new characters.

In Series 7 (2003) the programme title was officially shortened to Thomas & Friends, this name having been used on merchandise and video covers for three years previously.

This series saw the adoption of a centralised cast, including Thomas, Edward, Henry, Gordon, James, Percy, Toby and Emily.

[citation needed] Other major changes included a move to production in CGI (done for budgetary reasons), rather than the use of physical models, and the addition of a voice cast to support the established narrator.

2015 saw The Adventure Begins, a special coinciding with the 70th anniversary of the franchise, and Sodor's Legend of the Lost Treasure; Series 19 began airing that same year.

2016 saw some changes; longtime composers Robert and Peter Hartshorne (father and son team) left the series and Chris Renshaw and Oliver Davis took over.

This series saw many changes, such as Edward, Henry and Toby being removed from the Steam Team to make room for two new female steam engines named Nia (Africa) and Rebecca (UK),[33] and the narrator being replaced with Thomas talking to the audience (however, Mark Moraghan, the previous narrator said that he would still work on the series).

[39] On 5 February 2021, it was announced that Cartoon Network and Netflix had jointly picked up the broadcast and streaming rights to the series in the United States, respectively.

From Series 5 to 12, some larger-scale models were used for the narrow gauge characters, to more easily fit the complex mechanisms into them while retaining a sufficient level of detail.

In the ninth series, another large-scale Thomas model was built to be at the same scale as the narrow gauge engines and to provide greater possibilities for interaction.

Among the CGI switch in 2009, some of these models were put on display in a special exhibit at Drayton Manor Theme Park's Thomas Land.

[50] In 2004, Robert Hartshorne took O'Donnell and Campbell's place as composer, while Ed Welch became the show's songwriter from Series 8 to The Great Discovery.

Brenner had been a writer of several other children's animated series, such as Angelina Ballerina, Tractor Tom, Fireman Sam, Spot, Poppy Cat, and Binka, as well as being the creator of Caribou Kitchen and Humf, and writer for several magazines featuring children's characters such as The Real Ghostbusters, Fireman Sam, and Thomas's sister series Tugs.

Sharon Miller has also been the voice director since the second CGI animated film Misty Island Rescue, and continued to work on the series in this capacity until its end.

In the United States, the series had first appeared in the form of sequences on Shining Time Station, during the program's 1989 to 1995 run on PBS.

Thomas & Friends returned in the form of several direct-to-video releases during season 6 (2002 to 2003) and as a stand-alone half-hour program on PBS Kids.

The rights to broadcast the series through PBS expired in December 2017,[51][52] thus ending a period of almost 30 years of programming related to Thomas & Friends on American public television.

Mattel partnered with several companies, including Budge Studios and Animoca Brands, to create mobile apps based on Thomas & Friends.

[69] Common Sense Media rated the show a four out of five stars, writing, "Parents can be assured that this series has educational aspects as well as behavioural modelling.

The Thomas the Tank Engine stories were conceived by a young British boy early in the 20th century, who would listen to the trains as they chuffed through the countryside.

"[73] In 2011, a contributor for Slate analyzed the "hidden subtexts" of British imperialism in the series, while in 2013 Alex Knapp wrote for Forbes about the "baffling economics" of the Island of Sodor.