1540s

The 1540s refers to the years 1540 through 1549, a decade marked by continued religious upheaval, dynastic conflicts, and expanding global contact within the early modern world. It sits amid the broader conflicts of the Protestant Reformation and the Ottoman–Habsburg wars, as well as rapid growth in European overseas activity.

Religious and intellectual developments dominated continental affairs. The Society of Jesus (the Jesuits) was founded in 1540, becoming a key force in the Catholic Counter-Reformation. The Council of Trent began its long sessions in 1545, aiming to address doctrinal disputes and church reform. In England, Henry VIII’s kingdom continued its break with Rome through political-religious reforms, including his marriages in 1540 (to Anne of Cleves and subsequently Catherine Howard) and his death in 1547, which brought Edward VI to the throne. In science, Nicolaus Copernicus’s De revolutionibus was published in 1543, signaling a turning point in astronomical thought.

Military and political shifts also defined the decade. The Schmalkaldic War (1546–47) pitted the Habsburg-led Imperial forces against the Protestant Schmalkaldic League and culminated in the 1547 Battle of Mühlberg, reinforcing Imperial authority in parts of the Holy Roman Empire for a time. In France, Henry II began his reign in 1547, continuing the ongoing Italian Wars and shifting dynastic alliances. The period witnessed ongoing religious and political realignments across Europe, setting the stage for further reform and conflict.

Across the Atlantic realm, Spanish colonial ventures continued to expand, accompanied by regulatory attempts such as the 1542 New Laws aimed at reforming the encomienda system and improving governance in the Americas. The decade also saw intensified cross-cultural exchanges through exploration and maritime trade, contributing to broader global connections. Notable births include the astronomer Tycho Brahe in 1546.