St. Josaphat of Polotsk
St. Josaphat of Polotsk, born Ivan Kuntsevych in 1580 in Ukraine, joined the Order of Saint Basil the Great and became Archbishop of Polotsk in 1617. He promoted the Union of Brest, uniting Eastern Christians with the Roman Catholic Church, facing opposition, and ultimately martyrdom in 1623. He was canonized in 1867.