Jan Castor was born on 27th June 1954, in Włocławek. He was a musician, music composer, and poet. His real name was Wiesław Ruciński.
In 1973, he graduated from Secondary School No. 3 in Włocławek, and then started studying at the Faculty of Chemistry of the Nicolaus Copernicus University in Toruń, where he met the band Res Publica and soon became its leader. He continued performing with the band until 1980, and then he first immigrated to Australia, and from there to the USA. The band Res Publika was rebranded to Republika, and found a new lead singer in Grzegorz Ciechowski.
During his years as an expatriate, Jan Castor became a music composer, with his main focus on film music. He died on 21st April 2016, in Los Angeles. His ashes were interred at the Municipal Cemetery in Włocławek.