Great lovers: Heights of passion - Part two, N-Z

What causes some relationships to echo through the ages? Their joy? Their intensity? Their resilience? Or their triumph against the odds? Ariane Sherine concludes our two-day celebration of true romance by choosing 25 more couples who, in different ways, embody the power of love

When we think about "true love", we tend to do so through a haze of rose-petal confetti. Our idea of a great love affair is as likely as not to involve an enraptured couple, luminous with joy at having discovered each other.

Perhaps we picture them gazing longingly into each other's eyes; maybe they are sharing sweet kisses, waking entwined in one another's warm arms, or whispering endearments to be remembered affectionately for decades. In these imagined romances, any altercations are fleeting, any infidelity is unthinkable - and, of course, no separation lasts longer than a few nights.

Why, then, do so many of the relationships featured in this Valentine's Day selection of great romances defy the above description? If we exclude those still living out their stories, then only a very few of these couples - the lesser-known E B and Katherine White, perhaps, or Emil Zand#225;topek and Dana Zand#225;topkovand#225; - come close to embodying the kind of loving, lasting relationship we long to have for ourselves.

Several of our couples met while one or both were already attached; many remained so throughout the romance, while a surprising number were also unfaithful to their "great love". Long absences and unrequited desire feature frequently, and almost half the liaisons were volatile, two fatally so. Yet all are considered to be among the great love stories of the past millennium.

The answer may be that all relationships are imperfect, and few more so than those of artistic luminaries and statesmen. With notability comes temptation; with great success comes absence, often leading to loneliness and indiscretions. More importantly, no real-life romance could possibly live up to the fanciful notions of love that we are encouraged to believe in. As the song says, love is pain.

Those of us in love torture ourselves with thoughts of losing it; the loveless yearn for it, remembering only its delights and never its agonies. The wonder is not that most relationships falter, but that any last a lifetime. Yet they do, and many of those described in this lovers' canon give us cause for joy and hope. If their love endured war, poverty, infidelity, incarceration and the wrath of society, surely our own relationships can withstand less?

Another possibility is that we prefer tales of heartache and passion to those of quiet contentment, providing we don't have to live them out ourselves. We can enjoy the heady glow of Richard Burton and Elizabeth Taylor's brightly burning flame, yet not have to suffer the heat; we can empathise with Petrarch, Yeats and possibly Shakespeare's tortuous longing, yet not face comparable rejection.

Similarly, although we would never wish for it, nothing elevates a love story as poignantly as early death, which is why one of the loveliest of historical British romances is that of Victoria and Albert - a man who did little to charm the country but so won his Queen that Victoria spent half her life mourning his early death.

If it is true that passion makes for a great narrative, it is also no coincidence that many of the most notable artists' and poets' love lives were full of sorrow and intensity: their grief and elation suffused their art, making it greater in the process.

In 1893, the playwright Oscar Wilde wrote to his notoriously petulant lover, Lord Alfred Douglas (Bosie): "Dearest of All Boys, Your letter was delightful, red and yellow wine to me; but I am sad and out of sorts. Bosie, you must not make scenes with me. They kill me, they wreck the loveliness of life. I cannot see you, so Greek and gracious, distorted with passion. I cannot listen to your curved lips saying hideous things to me." Yet, despite Wilde's palpable anguish, Bosie's unpredictable behaviour influenced his most romantic letters, and is likely to have inspired some of his greatest work.

Of course, the answer to our question may merely be that legends of woe and strife are more memorable than tales of gentle constancy, even if ceaseless friendship through the trials of ageing and loss is in truth the greatest love of all. Suffering is more readable than bliss, and melodrama lends itself more readily to history than contentment. The stories that endure are those that capture the imagination, whether or not they represent love in all its fullness.

However, for all the caprices, clashes and destructive natures of the poets, actors and great characters in this selection of great lovers, there is one trait that distinguishes them from lesser couples, and renders them deserving of our affections: each firmly believed they had found their one true love. That many of them subsequently went on to throw it away is testament both to the difficult nature of love itself, and to the fallibility of humans.