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:
Crimean_War

Context:
In the spring of 1854 the Russians again advanced, crossing the Danube River into the Turkish province of Dobruja. By April 1854, the Russians had reached the lines of Trajan's Wall where they were finally halted. In the center, the Russian forces crossed the Danube and laid siege to Silistra from 14 April with 60,000 troops, the defenders with 15,000 had supplies for three months.:415 The siege was lifted on 23 June 1854. The English and French forces at this time were unable to take the field for lack of equipment.:415

Question:
When did the siege of Silistra end?

23 June 1854