"China" in Russian is "Китай (Romanize: Kitai). So where did that come from? Many history books explain the origin of "China", but not "Kitai".
Before the Mongolian conquered the Southern Song Dynasty and the Liao Dynasty, they were still in the Mongolian steppe. They looked south and saw the Liao Dynasty founded by Khitan people. So they called northern China "Khitan". Then they brought this term with the conquering of Moscow.
Not only the Russians call China "Kitai" today, but Marco Polo described northern China also with "Catai" during his visit. After returning to Venice, he joined a war, got captured, and shared his experience with Rustichello, who wrote a book about it. In turn, "Catai" morphed into "Cathay" in English.
Tsai Wan-lin established the Cathay Life Insurance. In British Hong Kong, an Australian and an American founded Cathay Pacific Airline. And its loyalty program is called the Marco Polo Club!