Of the many Chinese languages, Mandarin is considered the national standard for general communication and advanced academics. The indigenous and natural speakers of Mandarin are considered to be the people of China's north & northeast, but the ancient roots of Mandarin was born and evolved from Old Chinese of the Asian heartland that ranged from the Kunlun Mountains in the west, the Central Plains in the east, the grasslands in the north, and the Yellow River valley in the south; this is where the comprehensive development of the Altaic, Sino-Tibetan, Turkic, and Yeneiseian languages all began based on the most credible archaeological and historic evidence.
Cantonese is another popular spoken form and some people associate its "sound" with Vietnamese, but the dialect (whom some describe as a unique language such as between German and Italian) is likely the result of divergence and evolution from Old Chinese and Middle Chinese drift to the south and its resulting intermingling with the ancient Yue people (so-called Austro-Asiatic speakers) from Han Dynasty times before and after; and also some influence back northwards during the period of Middle Chinese development with population drifts during the Tang Dynasty, Northern Song Dynasty, and later Ming Dynasty eras.
The roots of Modern Mandarin had evolved from Old Chinese, and consists of native speakers (i.e. northeast, central plains, etc), native-regional speakers (provincial speakers with local dialect/language), and diaspora speakers (Taiwan, Singapore, etc), thus the myriad of unique accents of "Mandarin speakers". Old Chinese was spoken only before the period of the Three Kingdoms, a time where Chinese surnames were often multi-syllabic, and the number of surnames ranged in the thousands. This of course have simplified over the generations, and so has Chinese writing, including those used by Japanese and Korean nationals. The education systems of Hong Kong and Taiwan still support Traditional (complex) Chinese written form. Those who study Chinese calligraphy also study Traditional form in earnest.
Although historical linguistic studies are marred by ethnic and Euro-centric revisionist and nationalist views. The Chinese language likely evolved and co-evolved from an ancient language that gave birth to such classifications under Altaic, Sino-Tibetan, Turkic, and Yeniseian. What remain of the Yeniseian language are the 500 or so people of the Ket ethnicity in northwestern Siberia as of 2009, and is