Kashlyak Viktor Nikolaevich (29.07.1951-15.05.2013) - historian, local historian, writer, journalist. He was born on July 29, 1951, in Petropavl, North Kazakhstan region. He had higher education. From a young age, he engaged in the study of the history of the Semey region. More than 70 of his works on historical topics were published in scientific publications and periodicals of the Republic of Kazakhstan. In total, 110 articles were published in periodicals.

He conducted his research in the archives of Moscow, Leningrad, Tomsk, Almaty, Tobol, and Tyumen. When interesting documents were found, he would work with them until dawn. In 1998, he participated in the compilation of I.G. Andreev's book titled "Description of the Central Horde of the Kyrgyz-Kaisaks." In 1999, his authored work "Chronicle of the Streets of Semey" was published. In the summer of 1999, Viktor Nikolaevich led an expedition titled "In the Footsteps of A. von Humboldt in Russia," which took place in the city of Semey. The materials he prepared on this topic were published in one of the scientific collections of the Republic of Kazakhstan.

In 2001, he published a collection of festive postcards titled "Semey - Semipalatinsk" in collaboration with photographer Vlad Pavlun and designer Igor Ryabukhin, and that same year he also published a booklet titled "The Voskresensky Church of Semey." In 2002, a collection of articles dedicated to the history of the city titled "Semey. Three Centuries of History" was released. Later, his books "Semey: Named After Them," "Semey: From Burgomaster to Mayor," "Semey Press. 1863–1963," "The Voskresensky Church of Semey. 150 Years," "The Sacred Spring of Semey," "Temples of Semey: Past and Present" were published. He also released a two-volume work titled "Semey Arabesques." All of this is the result of tireless, diligent work that spanned many years of search and documentation. He was a true professional who only believed in concrete facts proven by historical documents. In February 2004, Viktor Nikolaevich, together with like-minded colleagues, founded the city local history society.

His last research topic was dedicated to documentary materials related to events and figures in the Semey region. However, he did not have the opportunity to complete this work. In 2013, Viktor Nikolaevich passed away.

Five years after his passing, in 2018, a book titled "People. Events. Data in Documents" was published. The manuscript was preserved thanks to his wife, Natalia Vadimovna, and was handed over to local historians.