"Men have died from time to time," said Rosalind, dismissing the ardent Orlando in Shakespeare's As You Like It, "and worms have eaten them, but not for love." Even Leander, claimed the irrepressible Rosalind, did not drown because he was trying to swim across the Hellespont to his beloved Hero on a stormy night. He was just going for a wash in the strait when he was overtaken by cramps that drowned him. What about women, though? No such prosaic explanation has ever sufficed for Cleopatra's death. Traditionally, the Egyptian queen has been surrounded with speculation and romantic mystery in spite of the nasty things that the Romans said about her. Neither can the Romans be blamed. She put two of their best, Julius Caesar and Mark Antony, serially in her pocket. She was using her legendary powers of seduction - research shows that those were more of wit and intellect than of superlative beauty - not only to ensure that Egypt did not become a Roman province and that she remained an independent queen, but it was also possible that she had an eye on the Roman empire, with her son with Caesar a possible claimant. Tough lady. Would such a woman die for love?

Rosalind would probably say no. Her creator is not quite so dismissive: the just dead Antony is definitely on Cleopatra's mind when the asp is on her breast, although it is the defeat in the hands of Octavius Caesar that appears to be the trigger for her suicide. She is hardly likely to be counted among the likes of, say, Princess Sophie of Saxe-Weimar-Eisenach, who, in 1913, killed herself when 25 presumably because her family would not let her marry a local banker's son. Cleopatra could, if deglamourized and shorn of her strategic love affairs, seem closer to India's Rani Durgavati, queen of Gondwana, who killed herself on the battlefield when unable to repulse the invading armies of Abdul Majid Asaf Khan after a valiant battle in 1564. But scientists - trust them to put a spanner in the workings of romance - have, though with commendable caution, come up with a new theory. Cleopatra's suicide could have been the culmination of a massive volcanic eruption in a land far away some years before she died. Painstaking reasoning based on a comparison of the study of river records and ice core deposits with documentation of floods, famines and social unrest in Egypt in scrolls has suggested this.

Total dependence on the floods of the Nile for agricultural prosperity lasted in Egypt till the Aswan Dam was built last century. In some years, the river did not flood. Findings of ash on ice core deposits that match records of a lack of flooding, scarcity, famine and social unrest have led scientists to propose that an enormous volcanic eruption in Nicaragua in 44 BC - the year Caesar was murdered and Cleopatra herself was in Rome - had long-lasting effects on the climate both to its east and west.

When Cleopatra was supporting Antony in his fight against Octavius Caesar, she could not have, the scientists believe, brought her own people together against a common enemy because they were wrapped up in distress and discontent. A study of the environment has offered history an interesting gloss. Will science solve Cleopatra's other mystery too? It seems asps do not have keen enough poison to kill. So what did happen then?

How far do weather events turn the tide in the history of kings and queens and battlefields? For Cleopatra, suggest scientists, they were the final straw