R. Chaim Kreiswirth was born in Wojnicz, Poland in 1918, the son of Rabbi Avrohom Yosef Kreiswirth. In his youth, he was well-known for his brilliance, excellent character traits and geniality, dubbed the "Cracower Illui" at age 15 in recognition of his prodigious powers of Talmudic analysis. With the 1939 German invasion of Poland, R. Chaim was forced to flee. Miraculously, he was saved from a German soldier's bullet when the soldier told him to run off as he shot into the air. He attributed this extraordinary occurrence to the merit of attending to a blind scholar.

Reaching Lithuania, he married the daughter of the Slabodka Mashgiach, R. Avrohom Grodzinski. The couple fled via Vilna to Palestine, where he settled into the yeshiva world and became friendly with many famous personalities. In 1947, Rabbi Kreiswirth moved to the United States to serve as Rosh Yeshiva in Hebrew Theological College in Skokie, Illinois, where he quickly established a rapport with his students, many of whom would rise to prominence in the burgeoning Orthodox community.

In 1953 he returned to rebuild the struggling community in Antwerp, despite concerns that his exceptional talents could be better used on the American continent instead of an insignificant post-holocaust European Kehilla. With vision, determination and inexhaustible energy, R. Kreiswirth devoted the rest of his life to the Belgian community and became the driving force and inspiration behind its growth. He served as Av Beth Din and Posek in Antwerp and was active in Agudath Israel, revered and consulted by thousands. He died on Sunday 30 December 2001 (16 Tevet 5762 on the Hebrew calendar) shortly before midnight, aged 82, after suffering from an illness.