The Xia dynasty lasted from 2070 BC until 1600 BC. It was the first ruling dynasty in Chinese history. The Xia was probably created by emperor Yu the Great. It is not known for certain if the Xia dynasty actually existed. Many people think that the Xia dynasty is only a legend. This is because there is no evidence that can prove that there was some dynasty before 1600 BC. There were found some archaeological excavations from 1500 BC which may come from the Xia dynasty. For example one of the excavations causes archaeologists to believe that the foundations of China were created during the Xia dynasty. Also there are findings of the oldest Chinese calendar called a lunar calendar. Xia dynasty was ended by a dynasty named Shang.