The organisation will own and manage rail infrastructure, issue contracts to private firms to run trains, set most fares and timetables, and sell tickets. It will absorb Network Rail in a bid to end the current "blame-game system" between train and track operations when disruption occurs.
But Ministers have been warned that "rebranding the railways will not solve the underlying problems for passengers" and that the changes risk failing to improve services in the North if local leaders aren't sufficiently involved.
The Williams-Shapps Plan for Rail has been published as a white paper. It is based on the recommendations of a review of the industry carried out by former British Airways chief executive Keith Williams following the chaotic introduction of new timetables in May 2018.
The plan was initially due to be published in autumn 2019 but was delayed by the general election and the coronavirus pandemic.
Prime Minister Boris Johnson said: "I am a great believer in rail, but for too long passengers have not had the level of service they deserve. By creating Great British Railways and investing in the future of the network, this Government will deliver a rail system the country can be proud of."
GBR is not expected to be established until 2023. Its logo will be an updated version of British Rail's double arrow. It will be released at a later date. Many reforms will be brought before the body is launched.
Flexible season tickets will be introduced, offering savings on certain routes for people who travel to work two or three times a week. These will go on sale on June 21 for use seven days later.
There will also be a "significant roll out" of more pay as you go, contactless and digital ticketing on smartphones, the Department for Transport (DfT) said.
Rail franchises were effectively ended when the Government took over the financial liabilities of operators in March 2020 to keep services running amid the collapse in demand caused by the coronavirus pandemic, at a cost of £10 billion.
The emergency agreements will be replaced by passenger service contracts, with GBR contracting private firms to operate trains.
This concession model is similar to the one used for London Overground and Docklands Light Railway services by Transport for London. The new body will specify most of the timetables and fares.
Operators will be incentivised to run high-quality services and increase passenger numbers.
Transport Secretary Grant Shapps said Britain's railways were built to "forge stronger connections" and provide "an affordable, reliable and rapid service", but passengers have been failed by "years of fragmentation, confusion and over-complication".
He declared: "That complicated and broken system ends today." He added: "Great British Railways marks a new era in the history of our railways.
"It will become a single familiar brand with a bold new vision for passengers - of punctual services, simpler tickets and a modern and green railway that meets the needs of the nation."
Mr Williams commented: "Our Plan is built around the passenger, with new contracts which prioritise excellent performance and better services, better value fares, and creating clear leadership and real accountability when things go wrong."
Sheffield City Region metro mayor Dan Jarvis said: "Rebranding the railways will not solve the underlying problems for passengers nor level up the North.
“Passengers must come first, and their needs must be put ahead of profits. In South Yorkshire and across the North we need transformational investment to upgrade our decrepit Victorian infrastructure and improve connectivity between Northern towns and cities.
“If this government want to be taken seriously on the levelling up agenda, this will be a key test that they must meet.”
Tracy Brabin, the Mayor of West Yorkshire, said: “Passengers in the North of England have long experienced the impact of disjointed rail services which have failed to address their needs.
“We must avoid swapping a fragmented railway for one run from Whitehall. I want to see a strong local voice in the way services are commissioned and run, which needs to be supported by the devolution of funding."
Henri Murison, director of the Northern Powerhouse Partnership, said “Today’s announcement is a vindication of the compelling cases made by Northern business and civic leaders following the May 2018 timetable fiasco.
"The franchise model was broken and not fit for purpose, and I have no doubt that the new body under the leadership of Sir Peter Hendy and Andrew Haines will deliver a more reliable, efficient Northern rail network.
“However, while the principle of local control set out today is the right one, without fully involving our Metro Mayors and civic leaders, there is a risk of northern services failing to meet what we need to drive our economic growth.
"Not going far enough on devolving control to Northern leaders, such as through Transport for the North, is a recipe for disaster and we will be making firm representations to government on the need to go further on devolving the North’s railways."
Tim Wood, Transport for the North’s Interim Chief Executive, said: “The North saw first-hand the effects of a fragmented rail industry during the 2018 timetable crisis.
"The fact that Great British Railways will bring track and train together as the guiding mind and put the needs of passengers first is a giant leap forward and something we’ve championed.
“This is a major national moment and a shift in how the railway is run. But this national approach must not be a missed opportunity for further devolution, giving the North’s leaders greater oversight of services and infrastructure investment to deliver more integrated regional networks that work for all."