to which the Spanish Empire did not adhere. Under British diplomatic pressure, the Spanish government signed a treaty in 1835 which pledged to eventually abolish slavery and the slave trade. In this context, black revolts in Cuba increased, and were put down with mass executions. One of the most significant was the Conspiración de La Escalera (Ladder Conspiracy), which started in March 1843 and continued until 1844. The conspiracy took its name from a torture method, in which blacks were tied to a ladder and whipped until they confessed or died. The Ladder Conspiracy involved free blacks and slaves, as well as white intellectuals and professionals. It is estimated that 300 blacks and mulattos died from torture, 78 were executed, over 600 were imprisoned and over 400 expelled from the island. (See comments in new translation of Villaverde's "Cecilia Valdés".) The executed included the leading poet (1809-1844), now commonly known as "Plácido". José Antonio Saco, one of Cuba's most prominent thinkers, was expelled from Cuba.