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:
Punjab,_Pakistan

Context:
The province is home to several historical sites, including the Shalimar Gardens, the Lahore Fort, the Badshahi Mosque, the Rohtas Fort and the ruins of the ancient city of Harrapa. The Anarkali Market and Jahangir's Tomb are prominent in the city of Lahore as is the Lahore Museum, while the ancient city of Taxila in the northwest was once a major centre of Buddhist and Hindu influence. Several important Sikh shrines are in the province, including the birthplace of the first Guru, Guru Nanak. (born at Nankana Sahib). There are a few famous hill stations, including Murree, Bhurban, Patriata and Fort Munro.

Question:
Who was the first Sikh Guru?

Guru Nanak