Isabel Luísa, Princess of Beira

Infanta Isabel Luísa Josefa of Portugal (6 January 1669 – 21 October 1690) was the only child of Peter II of Portugal and his first wife and former sister-in-law, Maria Francisca of Savoy. She was the heiress presumptive to the throne of Portugal between 1668 and 1689, when her half-brother John was born. As such, she was styled Princess of Beira.

Biography
Isabel Luísa was the only child of Peter II of Portugal and his first wife, the French born Princess Marie Françoise of Savoy. She was born at the Ribeira Palace, Lisbon, in 1669. Louis XIV sent a special envoy to congratulate her birth.

In age five, Isabel Luísa was declared heir presumptive to the Portuguese throne during the 1674 Cortes.

Marriage prospects
It was planned that she would marry Victor Amadeus II of Savoy, a first cousin through her aunt Marie Jeanne, Duchess of Savoy, then regent for her son. The marriage was opposed by most of the Savoyard court as it meant that Victor Amadeus would live in Portugal and his mother would remain in power. But that plan was not implemented.

Other proposed candidates included Gian Gastone de' Medici (future Grand Duke of Tuscany), le Grand Dauphin son of Louis XIV, Charles II of Spain, the Duke of Parma as well as a Count Palatine of Neuburg. Nothing came of these plans. For this she was nicknamed Sempre-noiva, "Always-engaged".

Death and burial
She died of smallpox at Palhavã in 1690, when she was 21 years old. Isabel Luísa is buried at the Monastery of São Vicente de Fora in Lisbon after being moved from the Convent of the Francesinhas.