Yuri Valentinovich Knorosov alternatively, Knorozov; in Russian: Юрий Валентинович Кнорозов; b. November 191922 — d. March 31 1999) was a Russian linguist, epigrapher and ethnographer, who is renowned for the pivotal role his research played in the decipherment of Maya hieroglyphics.

He was born near Kharkov in the Ukraine, into an academic Russian family. As a young man, Knorosov served in the Red Army during World War II as an artillery spotter. By some accounts he took part in the final push into Berlin during May, 1945, although later sources question this. Nevertheless, the following well-known anecdote has been published, possibly as a retrospective "embellishment" to his biography: the story goes that during this exercise he and his unit passed by the National Library as it was being consumed in a blaze. Knorosov apparently managed to retrieve from the building a one-volume edition containing copies of the three Maya codices which were then known. He later said that this chance discovery piqued his later lifelong interest in the subject area, although exactly how this work came into his possession is sometimes disputed.

After the war, Knorosov enrolled at the Russian Institute of Ethnography in Leningrad (present-day Saint Petersburg) to study ancient languages, specialising in comparative linguistics (he had apparently been previously enrolled at the Moscow State University in 1940 just prior to the war, which interrupted his study plans). At the instigation of a professor there, Knorosov wrote his dissertation on the "de Landa alphabet", a record produced by the 16th Century Spanish Bishop Diego de Landa in which he claimed to have transliterated the Spanish alphabet into corresponding Maya hieroglyphs, based on input from Maya informants. De Landa, who during his posting to Yucatán had overseen the destruction of all the codices from the Maya civilization he could find, reproduced his alphabet in a work (Relación de las Cosas de Yucatán) intended to justify his actions once he had been placed on trial when recalled to Spain. The original document had disappeared, and this work was unknown until 1862 when an abridged copy was discovered in the archives of the Spanish Royal Academy by the French scholar, Charles Etienne Brasseur de Bourbourg.

Since de Landa's "alphabet" seemed to be contradictory and unclear (e.g., multiple variations were given for some of the letters, and some of the symbols were not known in the surviving inscriptions), previous attempts to use this as a key for deciphering the Maya writing system had not been successful.

In 1952 Knorosov published a paper which was later to prove to be a seminal work in the field (Drevnyaya pis’mennost’ Tsentral’noy Ameriki, or "Ancient Writing of Central America".) The general thesis of this paper put forward the observation that early scripts such as ancient Egyptian and Cuneiform which were generally or formerly thought to be predominantly logographic or even purely ideographic in nature, in fact contained a significant phonetic component. That is to say, rather than the symbols representing only or mainly whole words or concepts, many symbols in fact represented the sound elements of the language in which they were written, and had alphabetic or syllabic elements as well, which if understood could further their decipherment. By this time, this was largely known and accepted for several of these, such as Egyptian hieroglyphs (the decipherment of which was famously commenced by Jean-François Champollion in 1822 using the tri-lingual Rosetta Stone artefact); however the prevailing view was that Mayan did not have such features. Knorosov's studies in comparative linguistics drew him to the conclusion that the Mayan script should be no different from the others, and that purely logographic or ideographic scripts were not actually so.

Knorosov's key insight was to treat the Maya glyphs represented in de Landa's alphabet not as an alphabet, but rather as a syllabary. He was perhaps not the first to propose a syllabic basis for the script, but his arguments and evidence were the most compelling to date. He maintained that when de Landa had commanded of his informant to write the equivalent of the Spanish letter "b" (for example), the Maya scribe actually produced the glyph which corresponded to the syllable, /bay/, as spoken by de Landa. Knorosov did not actually put forward many new transcriptions based on his analysis, nevertheless he maintained that this approach was the key to understanding the script. In effect, the de Landa "alphabet" was to become almost the "Rosetta stone" of Mayan decipherment.

A further critical principle put forward by Knorosov was that of synharmony. According to this, Mayan words or syllables which had the form consonant-vowel-consonant (CVC) were often to be represented by two glyphs, each representing a CV-syllable (i.e., CV-CV). In the reading, the vowel of the second was meant to be ignored, leaving the reading (CVC) as intended. The principle also stated that when choosing the second CV glyph, it would be one where the vowel sound matched that of the first glyph syllable. Later analysis has proved this to be largely correct.

Upon the publication of this work from a then hardly-known scholar, Knorosov and his thesis came under some severe and at times dismissive criticism. J. Eric S. Thompson, the noted British scholar regarded by all as the leading Mayanist of his day, lead the attack. Thompson's views at that time were solidly anti-phonetic, and his own large body of detailed research had already fleshed-out a view that the Maya inscriptions did not record their actual history, and that the glyphs were founded on ideographic principles. His view was the prevailing one in the field, and many other scholars followed suit.

The situation was further complicated by Knorosov's paper appearing during the height of the Cold War, and many were able to dismiss his paper as being founded on misguided Marxist-Leninist ideology and polemic. Indeed, in keeping with the mandatory practices of the time, Knorosov's paper was prefaced by a foreward written by the journal's editor which contained digressions and propagandist comments extolling the State-sponsored approach by which Knorosov had succeeded where Western scholarship had failed. However, despite claims to the contrary by several of Knorosov's detractors, Knorosov himself never did include such polemic in his writings.

Knorosov persisted with his publications in spite of the criticism and rejection of many Mayanists of the time. He was perhaps shielded to some extent from the ramifications of peer disputation, since his position and standing at the institute was not adversely influenced by criticism from Western academics.

During the 1960s, other Mayanists and researchers began to expand upon Knorosov's ideas. Their further field-work and examination of the extant inscriptions began to indicate that actual Maya history was recorded in the stelae inscriptions, and not just calendric and astronomical information. The Russian-born but American-resident scholar Tatiana Proskouriakoff was foremost in this work, eventually convincing Thompson and other doubters that historical events were recorded in the script.

Other early supporters of the phonetic approach championed by Knorosov included Michael D. Coe and David Kelley, and whilst initially they were in a clear minority, more and more supporters came to this view as further evidence and research progressed.

Through the rest of the decade and into the next, Proskouriakoff and others continued to develop the theme, and utilising Knorosov's results and other approaches began to piece together some decipherments of the script. A major breakthrough came during the first round table or Mesa Redonda conference at the Maya site of Palenque in 1973, when using the syllabic approach those present (mostly) deciphered what turned out to be a list of former rulers of that particular Maya city-state.

Subsequent decades saw many further such advances, to the point now where quite a significant portion of the surviving inscriptions can be read. Most Mayanists and accounts of the decipherment history apportion much of the credit to the impetus and insight provided by Knorosov's contributions, to a man who had not as yet set foot outside of his native Russia, but had still been able to make important contributions to the understanding of this distant, ancient civilisation.

As his theories became more widely known, Knorosov was in 1956 granted leave to attend an international convention of Mesoamerican scholars in Copenhagen. This was to be his one and only venture outside the Soviet Union for quite some time, since as a Soviet academic, Knorosov was subject to the usual restrictions placed on travel outside of the Soviet Union. Over subsequent years western Mayanists needed to travel to Leningrad to meet up with him. It was not until 1990 that he was eventually able to leave Russia again and finally visit the ancient Maya homelands and archaeological sites in Mexico and Guatemala. This was at the invitation of the Guatemalan President Marco Vinicio Cerezo Arévalo, at a time of improved diplomatic relations between the two countries. Cerezo presented him with an honorary medal, and Knorosov was able to extend his stay in the region, visiting several of the important Maya sites such as Tikal. However, shortly after Vinicio Cerezo left office, Knorosov received threats from suspected right-wing militarist groups who were antagonistic to the indigenous Mayan peoples, and was forced to go into hiding and then leave the country.

Knorosov had broad interest in, and contributed to, other investigative fields such as archaeology, semiotics, human migration to the Americas and the evolution of the mind. However, it is his contributions to the field of Maya studies for which he is best remembered.

In his very last years, Knorosov is also known to have pointed to a place in the United States as the likely location of Chicomoztoc, the ancestral land from which --according to ancient documents and accounts considered mythical by a sizable number of scholars-- Indian peoples now living in Mexico are said to have come.

Knorosov died in St. Petersburg on March 31, 1999, of pneumonia in the corridors of a city hospital, just before he was due to receive the honorary Proskouriakoff Award from Harvard University.

• 1952 - Knorosov, Yuri (1952). "Drevnyaya pis'mennost' Tsentral'noy Ameriki. (Ancient Writings of Central America)". Sovetskaya Etnografiya. 3: 100–118.
• 1954 - Knorosov, Yuri (1954). La antigua escritura de los pueblos de America Central. Biblioteca Obrera, Mexico City.
• 1956 - Knorosov, Yuri (1956). Diego de Landa: Soobshchenie o delakh v Yukatani, 1566. Akademia Nauk USSR, Moscow.
• 1958 - Knorosov, Yuri (1958). "New data on the Maya written language". Proc. 32nd International Congress of Americanists, (Copenhagen, 1956). pp. 467–475. {{cite conference}}: Unknown parameter |booktitle= ignored (|book-title= suggested) (help)
• 1958 -Knorosov, Yuri (1958). "The problem of the study of the Maya hieroglyphic writing". American Antiquity. 23: 248–291.
• 1963 - Knorosov, Yuri (1963). Pis'mennost Indeitsev Maiia. Akademia Nauk USSR, Moscow.
• 1967 - Knorosov, Yuri (1967). "The Writing of the Maya Indians". Russian Translation Series of the Peabody Museum of Archaeology and Ethnology. IV.

• "1998 address by Arthur Gould". Chicago Literary Club. Retrieved July 12. {{cite web}}: Check date values in: |accessdate= (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
• "Юрий Валентинович Кнорозов". Peoples RU. Retrieved July 19. {{cite web}}: Check date values in: |accessdate= (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help) (in Russian)
• Coe, Michael D. (1992). Breaking the Maya Code. Thames Hudson. ISBN 0-500-05061-9.