In classical times, a laurel wreath, made with the leaves of the bay tree, was worn on the head to signify victory or honor.

Knowles, Elizabeth. “laurel.” In The Oxford Dictionary of Phrase and Fable. Oxford University Press, 2005. https://www.oxfordreference.com/view/10.1093/acref/9780198609810.001.0001/acref-9780198609810-e-4007.

Mongols are members of different Asiatic ethnic groups, today primarily in Mongolia, Russia, and China. The term is used here in a pejorative manner to equate the Russians with savages. Historically, ‘Hun’ signifies a member of a warlike Asiatic nomadic group of people who, under Attila, their king, invaded and ravaged large parts of Europe in the late 4th and 5th centuries. During World War I, the term was used colloquially in a derogatory manner for Germans collectively, a reference to their barbarity in Belgium and France at the start of the war. Here, however, both Mongol and Hun are employed as racial slurs to denote the threat from East Asia and the Russian Empire.

"Hun, n.1 and adj.". OED Online. Oxford University Press, June 2021. https://www.oed.com/view/Entry/89450?rskey=4DzQZY&result=1.

The Mongol (Turkic) conqueror Tamerlane (also known as Timur, 1336–1405) established the Timurid Empire in present–day Afghanistan, Iran, and Central Asia.

“Tamerlane.” In World Encyclopedia. Philip's, 2014. https://www.oxfordreference.com/view/10.1093/acref/9780199546091.001.0001/acref-9780199546091-e-11334.