Martin Luther was a German theologian and religious reformer who is credited with initiating the Protestant Reformation in the 16th century.

Herman Bavinck was a Dutch Reformed theologian and author who lived from 1854 to 1921. He was a leading figure in the Dutch Reformed Church and is widely regarded as one of the most important Protestant theologians of the 19th and early 20th centuries.

John Calvin (1509-1564) was a French Reformer, pastor, and theologian considered among the greatest of the Protestant Reformation along with Martin Luther.

Benjamin Breckinridge Warfield was professor of theology at Princeton Seminary from 1887 to 1921. He served as the last principal of the Princeton Theological Seminary from 1886 to 1902.

Geerhardus Johannes Vos (March 14, 1862 – August 13, 1949) was a Dutch-American Calvinist theologian and one of the most distinguished representatives of the Princeton Theology. He is sometimes called the father of Reformed Biblical Theology.

Cornelius Van Til (1895-1987) revolutionized the world of apologetics. A 20th -century philosopher and theologian, Van Til attended Princeton Theological Seminary, wherein he received his ThM in 1925 and subsequently his Ph.D. in philosophy in 1927.