Short answers, pulled from the story.
Oracle bones from the Shang dynasty, dated to around 1250 BCE, bear the earliest known inscriptions of Chinese. These divinatory marks carved into animal bones and turtle shells represent a language that has evolved over three millennia.
Linguist Jerry Norman estimates hundreds of mutually unintelligible varieties exist within the Sinitic family. Mandarin accounts for 66% of speakers, roughly 800 million people, yet remains just one group among many.
The National Language Unification Commission settled on the Beijing dialect in 1932 after years of debate. This decision established Standard Chinese, now known as Putonghua, as the official language of both mainland China and Taiwan.
Xu Shen classified characters into six categories in 100 CE, noting only four percent were pictographs like ri or yue. Eighty to ninety percent became phonetic compounds combining sound and meaning components.
Northern Vietnam came under Han dynasty control in 111 BCE, beginning a millennium of Chinese administrative influence. Buddhist scriptures spread across East Asia between the 2nd and 5th centuries CE, carrying Literary Chinese with them.