Because the red flag was taken as an emblem early in the French Revolution. In July 1789, a law on martial law was passed in France, describing the actions of the municipality of Paris in emergency situations that pose a threat to the revolutionary government. As a symbol of martial law, it was prescribed to use a red flag hung from the main window of the town hall. A red flag was raised over the Champ-de-Mars in Paris on July 17, 1791, by Lafayette, commander of the National Guard, as a symbol of martial law, warning rioters to disperse. Inverting the original symbolism, the Jacobins protested this action by flying a red flag to honor the «martyrs' blood» of those who had been killed. They created their own red flags to declare «the martial law of the people against the revolt of the court». British sailors mutinied near the mouth of the River Thames in 1797 and hoisted a red flag on several ships. Two red flags soaked in calf's blood were flown by marchers in South Wales during the Merthyr Rising of 1831. It is claimed to be the first time that the red flag was waved as a banner of workers' power. During the Mexican siege of the Alamo in March 1836, General Antonio Lopez de Santa Ana displayed a plain red flag from the highest church tower in Bejar. At much the same time, the Liberal "Colorados" in the Uruguayan Civil War used red flags. This prolonged struggle at the time got considerable attention and sympathy from liberals and revolutionaries in Europe, and it was in this war that Garibaldi first made a name for himself and that he was inspired to have his troops wear the famous Red Shirts. The red flag was used by participants of Second Canut revolt in 1834 in Lyon. In 1848, red was the color of the rebels in France and Germany. Since 1871, after the Paris Commune, red has become the symbol of the international revolutionary movement of the proletariat. (See Thomas Carlyle, French Revolution; Feldman 2006)