A Pivotal Moment in European Religious Wars

On the night of March 24, 1587, Spanish ambassador Bernardino de Mendoza hastily dictated three urgent letters upon learning of Mary Stuart’s execution. This event would become the catalyst for one of the most consequential geopolitical and religious confrontations of the 16th century – Spain’s planned invasion of Protestant England under Elizabeth I.

Mendoza’s correspondence reveals the intricate web of Catholic alliances spanning Madrid, Brussels, and Rome. His first letter went to King Philip II of Spain, the second to the Duke of Parma in the Spanish Netherlands, and the third to Count Enrique de Guzmán, Spain’s ambassador to the Vatican. These three power centers formed what Mendoza envisioned as a trident aimed at England’s heart – with Madrid providing political will, Brussels supplying military force, and Rome offering spiritual legitimacy.

The Catholic World Mobilizes

Mendoza’s letters articulated a comprehensive Catholic response to Mary’s execution. He insisted the Scottish queen be recognized as a martyr, emphasized her secret bequest of English succession rights to Philip II, and warned of French duplicity. Most crucially, he advocated for William Allen’s elevation to Cardinal – positioning this exiled English priest to lead English Catholics when Spanish forces landed.

The ambassador’s strategic thinking reflected decades of Catholic frustration with Elizabeth’s England. Since her 1558 accession, Protestant England had become:
– A haven for Protestant rebels against Catholic rulers
– A supporter of Dutch independence from Spain
– A growing naval threat to Spanish Atlantic dominance

Rome had already excommunicated Elizabeth in 1570 (Regnans in Excelsis), releasing Catholics from allegiance to her. Now, Mary’s death provided the moral justification for decisive action.

The Players Behind the Conspiracy

### William Allen: Architect of Catholic Resistance

The 54-year-old Allen embodied English Catholic exile. After leaving Oxford in 1561 due to Protestant reforms, he founded seminaries in Douai (1568) and Rome (1579) to train missionary priests for England. His underground network sustained Catholic resistance through:
– Smuggling over 20,000 Catholic books into England
– Maintaining 300+ secret priests in noble households
– Coordinating with foreign Catholic powers

Allen’s 1584 treatise “A True, Sincere and Modest Defense of English Catholics” argued that deposing Elizabeth was morally justified. By 1587, he openly recognized Philip II as England’s legitimate sovereign.

### Robert Parsons: The Jesuit Operative

The 40-year-old Jesuit priest complemented Allen’s leadership with tactical brilliance. A convert from Protestantism, Parsons:
– Co-led the daring 1580 Jesuit mission to England
– Masterminded propaganda campaigns across Europe
– Negotiated directly with Philip II and the Pope

His 1587 work “A Brief Discourse” justified English Catholic soldiers defecting to Spanish service – a blueprint for expected mass defections during invasion.

The Vatican’s Calculated Response

Pope Sixtus V presented a paradox. While privately admiring Elizabeth’s statecraft (“What a valiant mind! How wisely she governs!”), he:
– Approved 1 million ducats for Spain’s invasion (payable upon landing)
– Accelerated plans to make Allen a Cardinal
– Authorized memorial masses for Mary as a martyr

The Pope’s actions revealed the Counter-Reformation’s geopolitical calculus – Protestant England’s elimination outweighed personal admiration for its queen.

Military Preparations and Strategic Assumptions

Spanish plans relied on key assumptions about England:
1. Military Weakness: “No city could withstand three days’ siege” against Spanish veterans
2. Catholic Sympathizers: Two-thirds of English would support or not resist invasion
3. Noble Networks: Northern Catholic families like Percys and Nevilles would rise up
4. Spanish Invincibility: The Army of Flanders was considered Europe’s finest fighting force

The Duke of Parma’s battle-hardened troops in the Netherlands stood ready to cross the Channel once Philip gave orders.

Why the Conspiracy Mattered

Mary’s execution and its aftermath directly led to:
– The 1588 Spanish Armada (though delayed by Drake’s Cadiz raid)
– Intensified persecution of English Catholics
– Elizabeth’s strengthened Protestant identity
– Lasting anti-Spanish sentiment in England

The events of March 1587 exemplify how early modern Europe’s religious conflicts intertwined with:
– Dynastic succession disputes
– Emerging nationalism
– Information warfare (via print propaganda)
– Transnational ideological networks

Legacy of a Failed Crusade

While Spain’s invasion ultimately failed, the Catholic resistance persisted. Allen became Cardinal in 1587, symbolizing Rome’s enduring claim over England. The seminaries he founded continued supplying priests to England for centuries, sustaining a Catholic underground until emancipation in the 19th century.

This episode reveals the 16th century’s central tension – whether political loyalty or religious faith should determine sovereignty. The answers forged in this crucible would shape the modern West’s church-state relations.