Roman gold coins found in St Albans have been bought by one of the city's museums for nearly £100,000.

The haord of 159 coins was found by metal detector on private land in October 2012 by a man making his first survey.

The find is believed to be one of the largest Roman gold coin hoards buried in the UK.

The coins date from the final years of Roman rule in Britain in the 4th Century and will go on display at Verulamium Museum from mid-September.

David Thorold, a curator at the museum, said: "The coins were issued under five emperors: Gratian, Valentinian II, Theodosius, Arcadius and Honorius.

"There are practically no other comparable gold hoards of this period. After AD 408, no further coin supplies reached Britain.

"The coins were made in the western mints of the Empire, mostly in the Italian cities of Milan, Rome and Ravenna.

"Evidence suggests that the coins were originally part of a hoard that had been disturbed at some point during the last couple of hundred years.

"During the period of the Roman occupation of Britain, people buried coins for two reasons, either as a sacrifice to their Gods or as a form of secure storage, with the aim of later recovery.

"Threat of war or raids might lead to burial in the latter case, as may the prospect of a long journey, or any other risky activity.

"Gold coins, known as solidi, were extremely valuable coins and were not traded or exchanged on a regular basis.

"They would have been used for large transactions such as buying land or goods by the shipload."

The coins, discovered by Westley Carrington during his first metal-detecting outing, were scattered across private land in the north of St Albans.

Richard Shwe, Head of Community Services at St Albans City and District Council, said: "I am delighted to be able to confirm that St Albans District Council has purchased the hoard of Roman gold coins.

"This purchase has been made possible with the generous support of the Heritage Lottery Fund, St Albans Museums and Galleries Trust and an overseas benefactor, who wishes to remain anonymous.

"The display will be accompanied by a programme of talks and activities for children and families."

An inquest in July 2013 declared the hoard treasure, giving the museum the right to acquire them, and the value was decided by an independent committee at the British Museum.