You will be given a definition of a task first, then an example. Follow the example to solve a new instance of the task.
Answer the question from the given passage. Your answer should be directly extracted from the passage, and it should be a single entity, name, or number, not a sentence.

Passage: Martin Luther married Katharina von Bora, one of 12 nuns he had helped escape from the Nimbschen Cistercian convent in April 1523, when he arranged for them to be smuggled out in herring barrels. Suddenly, and while I was occupied with far different thoughts, he wrote to Wenceslaus Link, “the Lord has plunged me into marriage. At the time of their marriage, Katharina was 26 years old and Luther was 41 years old. Question: In a letter who did Luther credit for his union with Katharina?
Solution: the Lord
Why? The paragraph clearly states that, Luther has credited the Lord for his union with Katharina, hence the Lord is correct answer.

New input: Passage: 'The Islamic State', formerly known as the 'Islamic State of Iraq and the Levant' and before that as the 'Islamic State of Iraq', (and called the acronym Daesh by its many detractors), is a Wahhabi/Salafi jihadist extremist militant group which is led by and mainly composed of Sunni Arabs from Iraq and Syria. In 2014, the group proclaimed itself a caliphate, with religious, political and military authority over all Muslims worldwide. As of March 2015[update], it had control over territory occupied by ten million people in Iraq and Syria, and has nominal control over small areas of Libya, Nigeria and Afghanistan. (While a self-described state, it lacks international recognition.) The group also operates or has affiliates in other parts of the world, including North Africa and South Asia. Question: What did the Islamic State proclaim itself in 2014?
Solution:
a caliphate