He was born in 1973 in Warsaw. Whilst still at high school, he had his first illustrations published in the Nowa Fantastyka magazine. He also drew for other publications, such as Fenix, Świat komiksu (The World of Comics) and Czas komiksu (The Time of Comics). In 1995 he prepared several hundred illustrations for an animated film series about World War Two, titled Ucieczki (The Escapes), directed by Marek Wortman. Kowalski’s comics have also been included in the cycle The Anthology of Polish Comics / Antologia polskiego komiksu (the volumes September: Drawn War / Wrzesień: Wojna narysowana, A Man in a Test Tube / Człowiek w probówce, and Best Young Draughtsmen / Najlepsi młodzi rysownicy)
The breakthrough in Kowalski’s career came with his individual, four-volume fantasy miniseries Gail, whose first part, Before the Storm (Przed burzą), was released in 2001. Even though the author has become quite critical towards it with time, it has allowed him to enter the French and Belgian scenes.
Grzegorz Rosiński has contributed to the artist's career development. They first met while promoting their respective albums in Poland. Rosiński later invited the young draughtsman to his place in Switzerland and supported him during the initial stage of his career, by e.g. sharing some technical hints. Kowalski came back from the trip with the series Le Branche Lincoln (with script by Emmanuel Herzet). Kowalski has also created other series for the French-speaking market: Dracula l'immortel (script by Michel Dufranne) and Urban Vampires (script by Eric Corbeyran).
