Alternative heirs to the English throne were named today following a worldwide quest to track down potential Kings and Queens.

Historical experts launched a bid to locate the ancestors of those who might have been crowned had William the Conqueror not won the Battle of Hastings.

Adverts were placed by English Heritage in newspapers across the globe, asking for people who could trace their family tree back to 1066 to get in touch.

Claimants had to prove links to either King Harold, Edward the Confessor, Edgar the Aetheling or Alfred the Great.

More than 500 people contacted the appeal and around 150 were shortlisted, A quarter came from the US, but others hailed from France, Italy, Norway, the Netherlands, Sweden, Australia and Canada.

Two of the strongest claims were from a financial director from Berkshire and an retired engineer in Newcastle.

Mark Golledge, from Berkshire, traced his family back to Alfred the Great through the "Stemmata Chicheleana" historical documents.

Published in 1765, they record all the descendants of Archbishop Henry Chichele, the founder of All Souls College, Oxford - who is related to Mr Golledge.

Mr Golledge said: "My family and I are very proud of our ancestry and very fortunate to have such a unique reference to illustrate our heritage."

Albert Turnbull, from Newcastle, was able to trace his lineage back to St Margaret and King Alfred but also to William the Conqueror, meaning his family may have had a claim regardless of the result at the Battle of Hastings.

The death of Edward the Confessor in 1066, leaving no children, led to conflict over the rightful heir to the English throne and ultimately to the Battle of Hastings.

Edgar the Aetheling - the "lost king" of England - was chosen as monarch but never crowned.

He was a direct descendent of Alfred the Great and the great-nephew of Edward the Confessor but was only 10 years old at the time and not considered experienced enough to defend the realm from the Normans and Vikings.

Harold Godwinson, a powerful nobleman, was chosen by the Witan council instead and became King Harold II.

But William the Conqueror's invasion and victory at the Battle of Hastings saw Harold killed and William take the throne.

Respondents had to submit documentary evidence supporting their lineage, along with the name of their most likely "gateway ancestor".

The research marked the opening of a new £2.3 million visitor centre at 1066 Battle of Hastings, Abbey and Battlefield in East Sussex.

Historians and genealogists were brought together to scrutinise the responses.

Dr Nick Barratt, from the BBC's Who Do You Think You Are? series, said they examined St Margaret of Scotland as the key to a royal lineage.

"A direct descendant of Alfred the Great, she was related to both Edward the Confessor and Edgar the Aetheling.

"If people can trace their lineage back to St Margaret, they're well connected to two of the key players, whose roles are explored in the interactive exhibition in the new visitor centre."

Judith Di-Sandolo, from Pontyclun, south Wales, has a family connection with the 15th Earl of Oxford, and from there back to St Margaret. She spent years researching the link.

A spokesman for English Heritage said: "The claims are still coming in. People are going into extraordinary detail, sending CD roms and huge family trees."

Mary McVicar, a Canadian, said she could trace her family back to Lady Godiva, while Jeremy Greville-Heygate from Leicestershire argued that his military experience, and large estate car stood him in good stead as a potential monarch.

In the past, monarchy was not necessarily a hereditary business.

It also came down to which noblemen had the biggest army and the most charisma.

Clarence House, the household of the current heir to the throne the Prince of Wales, has yet to comment on English Heritage's discoveries.