According to legend, the earliest accounts of coffee drinking can be traced to Ethiopia in the 9th century, when a goatherd named Kaldi noticed his goats became energetic after eating coffee berries. However, the earliest credible evidence of coffee drinking dates to 15th century Yemen. From Yemen, coffee spread to the Arabian Peninsula and was used by Sufi Muslims to stay awake for prayers. It then spread to North Africa, Turkey, and Persia in the 16th century. Coffee was introduced to Europe in the 17th century after Baba Budan smuggled coffee seeds out of Yemen to India. Coffee then spread worldwide and became one of the most valuable global commodities.