Families of British soldiers killed fighting in Iraq can bring damages claims against the government, the Supreme Court has ruled.
Relatives want to sue for negligence and to make claims under human rights legislation. Supreme Court justices announced on Wednesday that they can do both.
Families started legal action as a result of the deaths of a number of British soldiers following the American-led invasion of Iraq in 2003.
Their victory at the UK's highest court follows a hearing in London in February and means that claims can now proceed to trial.
Lawyers representing relatives say Corporal Stephen Allbutt, 35, was killed in a ''friendly fire'' incident in March 2003.
He died after a Challenger 2 tank was hit by another Challenger 2 tank. Trooper David Clarke, 19, also died during the incident.
Soldiers Dan Twiddy and Andy Julien were badly hurt in the incident, said lawyers.
Private Phillip Hewett, 21, of Tamworth, died in July 2005 after a Snatch Land Rover was blown up.
Similar explosions claimed the lives of Private Lee Ellis, 23, of Wythenshawe, Greater Manchester, in February 2006, and Lance Corporal Kirk Redpath, 22, of Romford, Essex, in August 2007, lawyers say.
Relatives say the Ministry of Defence (MoD) failed to provide armoured vehicles or equipment which could have saved lives, and should pay compensation.
The MoD says decisions about battlefield equipment are for politicians and military commanders.
Shubhaa Srinivasan, from law firm Leigh Day, who represents all the Challenger claimants, said:
"The highest court in the land has now ruled the MoD, as employer, must accept that it owes a duty of care to properly equip service personnel who go to war.
"We have constantly argued that the MoD's position is morally and legally indefensible.
"The claimants' claims have always been about decisions taken on provision of adequate equipment and training to British troops which are far removed from the battlefield.
"This equipment ranges from the very basic such as GPS devices, to sophisticated satellite tracker systems, which the Americans had available to them.
"It seems incredible that it was often left up to soldiers themselves to buy this equipment as they felt compelled to, so as to better protect their own lives and the lives of those they were responsible for.
"The MoD argument that if they accept a duty of care it would inhibit decisions on the battlefield or undermine morale and military discipline seems to defy logic.
"We argue that morale can only be improved if the Army accepts this duty of care and does everything in its formidable powers to reduce the risks for service personnel on the battlefield."
The Equality and Human Rights Commission deputy director, legal, Wendy Hewitt said: "The Supreme Court's ruling means that human rights protections have been levelled up so that we are no longer expecting our armed forces to fully respect the rights of civilians abroad while not being properly protected themselves.
"From this basic principle it is now up to the courts to decide how this should apply in practice.
"This is not about interfering with the way military decisions are made in the field but how everyone serving in the armed forces is given the protections they deserve."
Lawyer Jocelyn Cockburn, who also represented relatives and works for law firm Hodge Jones & Allen, said after today's ruling: "I think what they have established is what seems to many families is common sense - that soldiers have human rights, and they do remain within the jurisdiction of the UK, and they don't lose those because they are on the battlefield."
She added: "It is clearly in the public interest that the authorities are legally required to consider the safety of their soldiers in times of military conflict. Safety will not be the only consideration or even perhaps the primary consideration but it is right that our soldiers should expect to be properly equipped."