- March 11, 2004:
7:37 am: Bombs explode almost simultaneously on four trains linking the eastern Madrid suburb of Alcara de Henares to the central Atocha station.
A total of 191 people die and 1,841 are injured; the attacks come three days before an election that the conservative government is widely expected to win.
Within hours, a government spokesman blames the attacks on the Basque separatist group ETA, which issues a denial.
Detonators and a tape recording of verses from the Muslim holy book the Koran are found in a stolen van near Alcara de Henares.
The London-based newspaper Al-Qods al-Arabi receives a claim of responsibility for the attacks from "Abu Hafs al-Masri Brigades/Al-Qaeda."
The statement says the bombings are a response to Spain's role in the US-led war in Iraq.
- Friday March 12:
More than 11 million Spaniards take part in nationwide protest marches over the bombings.
Despite mounting evidence to the contrary, the government continues to insist that ETA is the most likely suspect.
- March 13:
Spain announces the arrests of three Moroccans and two Indians, and the discovery near a Madrid mosque of an Arabic-language videotape claiming the attacks on behalf of Al-Qaeda.
- Sunday, March 14:
Amid widespread anger over both the bombings and the government's reaction to them, the opposition Socialist Party wins the election.
- March 15:
Prime minister-elect Jose Luis Rodriguez Zapatero vows to honour his election pledge to withdraw Spain's troops from Iraq.
- April 3:
Seven key suspects blow themselves up during a police raid on their flat in a Madrid suburb. A policeman also dies in the blast.
- April 8:
Police find a video in the debris of the flat showing three men reading a statement in Arabic demanding the withdrawal of Spanish troops "from Muslim lands."
- May 21: The last Spanish troops leave Iraq.
- April 11, 2006:
A magistrate charges 29 people over the attacks. Charges against one are later dropped.
- April 15, 2007:
The trial opens in Madrid, with several key suspects pleading not guilty.
- July 2, 2007: Trial ends.
- Oct 31:
The court convicts 21 of the 28, but acquits an Egyptian who had been presented as one of the three masterminds behind the bombings.