Decimus et Ultimus Barziza was born in Virginia in 1838 to Phillip Ignatius Barziza, a former Venetian viscount who had emigrated to America and relinquished his title to qualify for a family inheritance. Barziza’s father married a French-Canadian, and together they had ten children, naming their youngest "Decimus et Ultimus"—Latin for "tenth and last." After attending the College of William & Mary from 1854 to 1857, Barziza was drawn to Texas, where he enrolled at Baylor University’s law school. Graduating in 1859, he established a law practice in Owensville, preparing for a promising career in his adopted state.