Leader of the Cuban opposition group Ladies in White, Laura Pollan, died yesterday at age 63, after complications from a respiratory virus and dengue fever.

The group was founded in 2003 in an effort to free political prisoners. Pollan’s crusade began after her own husband, Hector Maseda, was one of 75 men jailed for accusations of receiving money from foreign countries to fund counterrevolutionary activities.

Some prisoners, which included activists, social commentators and opposition leaders, received sentences for as long as 28 years.

The European Union responded by freezing relations with Cuba for over a year. In 2005, European Parliament honored Ladies in White with the Sakharov prize, a prestigious human rights award, although the Cuban government refused to allow Pollan to travel to Europe to accept the award.

The organization called themselves Ladies in White because of the white attire they wore and the gladiolas they carried every Sunday in Havana during marches against the government. The group started with a dozen women and grew to about 30 members.

The Cuban government eventually freed all 75 men. The last two were freed 21 March, 2011, the same day Castro announced his retirement as Head of the Communist Party.