:smack: 
The Kims, of N. Korea, speak every language in the world, fluently. Natch. 
All these other people were mere world leaders. Tolkien was a world creator.
Oops.
But how about a literary leader? An artistic leader?
I wasn’t aware Gothic was a language? Gonna read up on that!
The current Pakiatani President can speak, English, Urdu, Punjabi, Sindhi and Balochi.
There is a partial copy of a Bible that was translated into Gothic and a few other scattered documents. From these, modern linguists have been able to recreate the Gothic language. And then Tolkein decided to go ahead and write some poems in Gothic. So we have an unusual situation where the only original literature we have that was composed in a language was written over a thousand years after the language had died.
Sukarno, the first president of Indonesia, was fluent in several languages. In addition to the Javanese language of his childhood, he was a master of Sundanese, Balinese and of Indonesian, and especially strong in Dutch. He was also quite comfortable in German, English, French, Arabic, and Japanese.
On the Chinese side of the house
Deng Xiaoping spoke Sichuanese, Mandarin and some French. At least he picked up a preference for croissants from his time in France.
Lee Teng-hui, former President of Taiwan, spoke Taiwanese, Japanese, Mandarin and English. Ironically enough, Mandarin seemed to be his worst language.
Atta unsar, þu in himinam, weihnai namo þein, qimai þiudinassus þeins, wairþai wilja þeins, swe in himina jah ana airþai. Hlaif unsarana þana sinteinan gif uns himma daga, jah aflet uns þatei skulans sijaima, swaswe jah weis afletam þaim skulam unsaraim, jah ni briggais uns in fraistubnjai, ak lausei uns af þamma ubilin; unte þeina ist þiudangardi jah mahts jah wulþus in aiwins.
Codex Argenteus ; or ; The Silver Bible.
I read many years ago that the Swedish 17th century king Gustaf II Adolf handled five languages, including Gaelic, fluently and could manage another five.