Penelope was the daughter of Icarius, a Spartan prince, and the nymph Periboea, though some said her mother was the wise Polykaste. She grew up in the palace at Sparta, the great city in the Peloponnese famous for its warriors and its beautiful women, and when she came of age she attracted the attention of Odysseus, the king of Ithaca, a rugged island kingdom in the Ionian Sea off the western coast of Greece. Odysseus was not the most handsome of the suitors who sought her hand, nor the richest, but he was the cleverest, and Penelope chose him. The marriage was celebrated with feasting and gifts, and the couple were happy. They had one son, Telemachus, and for a brief time the palace of Ithaca rang with the sounds of a family at peace. Then the Trojan War began.

The war was fought because Paris, a prince of Troy, had abducted Helen, the most beautiful woman in the world and the wife of Menelaus, the king of Sparta. All the kings of Greece had sworn an oath to defend Helen's marriage, and Odysseus, though he had tried to avoid the war by pretending to be mad, was bound by that oath. He sailed with the Greek fleet to Troy, leaving Penelope and the infant Telemachus behind. The war lasted ten years, and when it ended Odysseus set sail for home. But the journey that should have taken weeks stretched into ten years of wandering, storms, monsters, and divine punishment, a story told in the Odyssey, the epic poem that bears his name. For twenty years in total, Penelope ruled Ithaca alone, a queen without a king, a wife without a husband, a mother raising a son who grew from a child into a man without ever knowing his father.

The suitors began to arrive soon after the war ended and Odysseus failed to return. They were the young nobles of Ithaca and the surrounding islands, men who saw an opportunity in the absence of the king. They came to the palace not as guests but as occupiers, eating Penelope's stores, drinking her wine, slaughtering her cattle, and demanding that she choose one of them as her new husband. There were a hundred and eight of them in the end, led by Antinous, the most arrogant and violent of the lot, and Eurymachus, the smooth-tongued flatterer who pretended to care for Telemachus while plotting his death. They filled the great hall with their noise and their filth, and they made Penelope's life a torment. She could not simply refuse them, for in the Greek world a woman without a husband or a father was vulnerable, and the suitors had the support of many of the island's families. But she could delay, and delay she did, with a cunning that would have made her husband proud.

The ruse of the shroud was her masterpiece. She announced to the suitors that she would choose a husband only when she had finished weaving a burial shroud for Laertes, Odysseus's father, who was old and nearing death. The suitors, eager to believe that their wait would soon be over, agreed. Penelope set up her great loom in the hall where all could see her work, and by day she wove the cloth with skill that was famous throughout the Greek world. But each night, when the palace was dark and the suitors slept, she crept to the loom and unravelled everything she had done that day, picking out the threads by the light of a torch so that the shroud never grew longer. For three years she kept this up, and the suitors, though they grew suspicious, could not prove her deception. It was finally revealed by one of her maids, Melantho, a disloyal servant who had taken the suitors' side, and the suitors forced Penelope to finish the shroud. But by then, unknown to anyone in the palace, Odysseus was already on his way home.

When Odysseus finally reached Ithaca, he came in disguise. Athena, the goddess who had favoured him throughout his wanderings, transformed him into an old beggar, ragged and bent, so that he could enter his own house without being recognised by the suitors who would have killed him on sight. He was taken in by Eumaeus, the loyal swineherd who had remained faithful to his master's memory for twenty years, and from there he made his way to the palace. Penelope, hearing that a beggar had news of her husband, summoned him to her chamber. She questioned him carefully, testing his knowledge of Odysseus's appearance and travels, and the beggar answered with details so precise that she felt a stirring of hope she had not allowed herself in years. But she did not yet believe him. She had been deceived before by travellers who claimed to have seen Odysseus, and she would not be made a fool of again.

The test she devised was the most famous in all Greek myth. She announced to the beggar that she would hold a contest for the suitors: whoever could string the great bow of Odysseus, a weapon of horn and sinew so stiff that no man but its owner had ever bent it, and shoot an arrow through twelve axe-heads set in a line, would win her hand. The suitors tried and failed one by one, their hands too weak, their pride too great. Then the beggar asked to try. The suitors laughed at him, but Penelope, on the advice of the beggar himself, allowed it. He took the bow, strung it with ease, and sent the arrow through all twelve axe-heads in a single shot. Then he turned on the suitors, and with the help of Telemachus and two loyal servants, Eumaeus the swineherd and Philoetius the cowherd, he slaughtered them all, Antinous first, then Eurymachus, then the rest, until the hall ran with blood and the suitors lay dead among the overturned tables.

But Penelope still did not believe that this man was her husband. She had been too careful for too long to accept a face she did not recognise. She ordered her maid Eurycleia, the old nurse who had raised Odysseus from birth, to prepare the marriage bed in the chamber that had been built around the trunk of an ancient olive tree, a bed that Odysseus had carved from the living wood himself and that could not be moved because it was rooted in the earth. When the beggar heard her speak of moving the bed, he cried out in anger, for he knew, as only the man who had built it could know, that the bed was immovable. It was then that Penelope knew him. She ran to him, weeping, and embraced him, and for the first time in twenty years the queen and king of Ithaca were together again. The reunion was one of the most moving scenes in all ancient literature: two people who had aged and suffered and changed, recognising each other not by appearance but by the shared secret of a bed that could not be moved.