You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Black_people

Context:
In the 18th century, the Moroccan Sultan Moulay Ismail "the Bloodthirsty" (1672–1727) raised a corps of 150,000 black slaves, called his Black Guard, who coerced the country into submission.

Question:
When did the Black Guard exist?

In the 18th century