Lady Mary Grey

Lady Mary Grey, (about) 1545–1578, was the youngest of the Grey sisters, and through her maternal grandmother Mary Tudor, she was close to the throne of England. Since Queen Elizabeth was childless, the two surviving Grey sisters were in the line of succession under King Henry VIII's will, and they were not permitted to marry without the Queen's consent. In 1560, Lady Katherine had flaunted that permission by marrying Edward Seymour, 1st Earl of Hertford.

Despite the disastrous consequences of her sister’s secret marriage, Mary also married without the Queen's permission. In 1565, while the Queen was absent from court, Mary secretly married the Queen's sergeant porter, Thomas Keyes. The marriage was unsuitable for many reasons. Keyes was from a minor gentry family, was more than twice Mary's age, and was a widower with six or seven children.

The newlyweds never saw each other again. Thomas Keyes was sent to Fleet Prison, and Lady Mary was put under house arrest and sent to Chequers Court in Buckinghamshire, where she stayed for two years. In 1567, Mary, still under house arrest, was sent to live with her step-grandmother Katherine, Duchess of Suffolk, for another two years before being sent to Sir Thomas Gresham at his house in Bishopsgate.

After seven years of house arrest and the death of Thomas Keyes, the Queen relented and allowed her to live where she pleased. With little income and no friends, she ended up briefly in the home of her mother’s second husband, Adrian Stokes, who had recently remarried. But by the end of 1577, she had found favour again and was appointed one of the Queen's Maids of Honour.

In April of 1578, the plague ravaged London, and Mary became ill. She drew up her will and died three days later, on April 20, 1578, aged 33. The Queen granted her an imposing funeral in Westminster Abbey, where she was buried in her mother's tomb.

Sources:

The Sisters Who Would be Queen: The Tragedy of Mary, Katherine & Lady Jane Grey, Leanda de Lisle

A Treasure of Royal Scandals, Michael Farquhar