Franciscus Junius the Elder (born François du Jon, 1 May 1545 – 13 October 1602) was a Reformed scholar and theologian.
 Born in Bourges in central France, he initially studied law, but later decided to study theology in Geneva under John Calvin and Theodore Beza.
 He became a minister in Antwerp, but was forced to flee to Heidelberg in 1567.
 He wrote a translation of the Bible into Latin with Emmanuel Tremellius, and his "De Vera Theologia" was a text in Reformed scholasticism.
Pieter Datheen, Latin Petrus Dathenus, English, Peter Datheen, (Cassel, Nord, c.1531 - Elbing, 17 March 1588) was a Dutch Calvinist theologian who accomplished many things for the advancement the Reformed Church liturgy.
 First, he translated the Heidelberg Catechism into Dutch.
 Second, using the singing work of John Calvin,Theodore Beza, Peter Marot, and Louis Bourgeois, Datheen set the Psalms and psalter to verse and tune in Dutch (1566), though his settings were overshadowed by those of Philips Marnix van St Aldegonde.
 Third, he wrote the famous "Form for the Administration of Holy Baptism" with its very orthodox emphasis on the Covenant of Grace containing two parts.
 Fourth, he wrote the equally famous "Form for the Administration of the Lord's Supper" still used by orthodox Reformed churches today.
 Fifth, he was President of the Convent of Wesel in 1568, which expressed hope for the Reformed Churches to be free from the awful persecution of Spanish Roman Catholics, and more significantly President of the 1578 Synod of Dordt.
 Sixth, at this latter Synod he helped write, edit, and approve the long-revered Church Order (more famously known as the 1618-1619 Church Order of Dordt) with its 84 articles.
 Seventh, he developed the liturgy (order of worship) used by orthodox Dutch and American Reformed Churches with the singing, alms, prayer, and preaching at the required places.
 Eighth and finally, during Roman Catholic Spain's very intense persecution of the Lowlands region, resulting in the deaths of 100,000 - 200,000 Reformed Christians, Datheen was a field preacher carrying his pulpit on his back and then orating to crowds of 15,000 in a blunt eloquence that was intense and captivating.
Guido de Bres (also known as Guido de Bray, Guy de Bray and Guido de Brès, 1522 – 31 May 1567) was a Walloon pastor and theologian, a student of John Calvin and Theodore Beza in Geneva.
 He was born in Mons, County of Hainaut, Southern Netherlands, and martyred at Valenciennes, aged 45.
 De Bres compiled and published the Walloon Confession of Faith known as the Belgic Confession (1561) ("Confessio Belgica") still in use today in Belgium and the Netherlands.
 It is also used by many Reformed Churches all over the world.
Jacobus Arminius (October 10, 1560 – October 19, 1609), the Latinized name of the Dutch theologian Jakob Hermanszoon from the Protestant Reformation period, served from 1603 as professor in theology at the University of Leiden.
 He wrote many books and treatises on theology, and his views became the basis of Arminianism and the Dutch Remonstrant movement.
The Calvin Auditorium or Calvin Auditory (French "Auditoire de Calvin"), originally the Notre-Dame-la-Neuve Chapel, is a chapel in Geneva, Switzerland, which played a significant role in the Protestant Reformation.
 It is associated with John Calvin, Theodore Beza and John Knox.
The Right of Magistrates (French: "Du droit des magistrats" , Latin: "De jure magistratuum" ) is a 1574 work written by Theodore Beza, and anonymously "published by those from Magdeburg of 1550", as a polemical contribution to the pamphlet literature of the French Wars of Religion.
 It emphatically protested against French state tyranny in religious matters, and affirmed the resistance theory that it is legitimate for a people to oppose an unworthy magistracy in a practical manner and if necessary to use weapons and depose them.
Protestantism in France has existed in its various forms starting with Calvinists and Lutherans since the Protestant Reformation.
 John Calvin was a Frenchman, as well as numerous other Protestant Reformers including William Farel, Pierre Viret and Theodore Beza, who was Calvin's successor in Geneva.
 Peter Waldo (Pierre Vaudes/de Vaux) was a merchant from Lyons, who founded a pre-Protestant group.
 Martin Bucer was born to German minority in Alsace, which historically belonged to the Holy Roman Empire, but now belongs to France.
Arminianism is based on theological ideas of the Dutch Reformed theologian Jacobus Arminius (1560–1609) and his historic supporters known as Remonstrants.
 His teachings held to the five solae of the Reformation, but they were distinct from particular teachings of Martin Luther, Huldrych Zwingli, John Calvin, and other Protestant Reformers.
 Jacobus Arminius (Jakob Harmenszoon) was a student of Theodore Beza (Calvin's successor) at the Theological University of Geneva.
 Arminianism is known to some as a soteriological diversification of Protestant Calvinist Christianity.
 However, to others, Arminianism is a reclamation of early Church theological consensus.
Claude D'Espence was a French theologian and diplomat, born in 1511 at Châlons-sur-Marne; died 5 Oct., 1571, at Paris.
 He entered the Collège de Navarre in 1536, and later became the rector of the Sorbonne before he got his doctorate.
 He was involved with the Council of Trent and argued against the Protestant apologist Theodore Beza about the value of tradition.
Theodore Beza (Latin: "Theodorus Beza" ; French: "Théodore de Bèze" or "de Besze"; June 24, 1519 – October 13, 1605) was a French Protestant Christian theologian and scholar who played an important role in the Reformation.
 A member of the monarchomaque movement who opposed absolute monarchy, he was a disciple of John Calvin and lived most of his life in Switzerland.

Question: Who was a professor of theology at the University of Leiden as well as a student of Theodore Beza?
Answer: Jacobus Arminius