Casimir Zeglen, CR (Polish: Kazimierz à »egleà Â; 4 March 1869 â before 1927) was a Polish Catholic priest who invented a silk bulletproof vest in the late 19th century. He was a vowed member of the Resurrectionists.
Born in 1869 in Kaczanówka near Tarnopol, at the age of 18 he entered the Resurrectionist Order in Lwów (today Lviv). In 1890, he moved to the United States. He was the pastor of St. Stanislaus Kostka Catholic Church in Chicago, then the largest Polish church in the country, with 40,000 in the parish.
In his early twenties, he began experimenting with cloth armour, using steel shavings, moss, and hair. In his research, he came upon the work of Dr. George E. Goodfellow, who had written about the bullet-resistive properties of silk. In 1893, after the assassination of Carter Harrison Sr., the mayor of Chicago, he worked on an improved silk bulletproof vest. In 1897, he went into partnership with Jan Szczepanik. Though the two parted ways, with Zeglen focusing on the United States and Szczepanik on Europe, a carriage covered with Szczepanik's bulletproof armour saved the life of Alfonso XIII, the King of Spain, when a bomb exploded near it.
In his mid-thirties Zeglen discovered a way to weave silk, to enable it to capture bullets, while visiting weaving mills in Vienna, Austria and Aachen, Germany. A thick, four-ply bulletproof vest produced there was able to protect the wearer from the lower velocity pistol bullets of that era. Zeglen offered a vest to President McKinley, who refused the gift, while Archduke Franz Ferdinand chose not to wear his vest when shot: tests and analysis suggest wearing a vest might have saved both.
He died in 1927.