Four new RAF F-35 Lightning stealth fighter jets have landed in the UK.
The jets, which cost £92m each, made the 3,000-mile journey across the Atlantic from a US Marine Corps base in South Carolina.
The supersonic planes will be based at RAF Marham in Norfolk, where they are expected to be in operation by the end of December.
The UK's military has committed to purchasing 138 of the US planes from aviation company Lockheed Martin.
A fifth jet which set off from the US Marine base returned to South Carolina after the aircraft took fuel from an airborne RAF tanker.
The planes had been due to fly to the UK on Wednesday, but the mission was postponed due to adverse weather conditions.
They will be part of the recently reformed 617 squadron - nicknamed The Dambusters after one of the squadron's missions during World War Two.
Why the RAF's new F-35 jets matter
By Jonathan Marcus, defence and diplomatic correspondent
The arrival of the first four F-35B Lightning II combat aircraft in Britain - a programme more widely known as the Joint Strike Fighter - marks a significant moment for the RAF in a year during which it has been celebrating its centenary.
The entry into service of the F-35B - which will be flown by both RAF and Royal Navy pilots - heralds the revival of Britain's ability to launch sea-borne operations from aircraft carriers. But it is much more than this.
The F-35B, according to Douglas Barrie, senior fellow for military aerospace at the IISS, "is the first aircraft that will enter British service designed from the outset to be low-observable, that is stealthy. This provides greater survivability than previous aircraft designs."
They can land vertically, similar to the Harrier Jump Jet, but the four fighters landing in Norfolk used the runway.
Earlier Air Commodore David Bradshaw said: "The reason we are not going to land vertically is that it goes back to that risk management, do we need to land vertically? No.
"Is there a little bit more of a risk doing that? Potentially."
"So after that length of sortie we just want to put the aircraft safely on the ground and we will come to vertically landing them here in the future."
F-35 fighter jet simulator unveiledThe journey took the four pilots about eight or nine hours.
Another five F-35s are expected to arrive at RAF Marham in July.
Defence Secretary Gavin Williamson described the jets as "game-changing".
"These formidable fighters are a national statement of our intent to protect ourselves and our allies from intensifying threats across the world," he said.
Getty ImagesThe RAF F-35Bs arrived at RAF Marham on Wednesday eveningThe aircraft were first used in combat by the Israeli air force.
In May it showed an image of jets over Beirut, Lebanon, and said the planes had "already attacked twice on two different fronts".
Israel recently carried out air strikes in Syria.
Allow Twitter content?
This article contains content provided by Twitter. We ask for your permission before anything is loaded, as they may be using cookies and other technologies. You may want to read and before accepting. To view this content choose ‘accept and continue’.Accept and continue
Earlier the Defence Infrastructure Organisation said it was investing about £250m in RAF Marham to cater for the new F-35 aircraft.
The money is being spent on resurfacing runways, building a hangar and headquarters for 617 Squadron, as well as three vertical landing pads.
BBC in other languagesInnovationncG1vNJzZmivp6x7o67CZ5qopV%2Bjsri%2Fjq6iZmxkaIZzfZNx