March 31

After divorcing his wife Minervina, Constantine marries Fausta, daughter of the retired Roman emperor Maximian.

In 307 AD, Constantine the Great ends his marriage to Minervina and weds Fausta, daughter of former emperor Maximian, to strengthen his dynastic ties.

Bernard of Clairvaux preaches his famous sermon in a field at Vézelay, urging the necessity of a Second Crusade. Louis VII is present, and joins the Crusade.

In 1146, Bernard of Clairvaux’s stirring sermon at Vézelay ignites Europe’s call for a Second Crusade, with King Louis VII pledging his support.

A conspiracy against Saladin, aiming to restore the Fatimid Caliphate, is revealed in Cairo, involving senior figures of the former Fatimid regime and the poet Umara al-Yamani. Modern historians doubt the extent and danger of the conspiracy reported in official sources, but its ringleaders will be publicly executed over the following weeks.

In 1174, a plot to overthrow Saladin and reinstate the Fatimid Caliphate is exposed in Cairo, leading to the execution of its alleged ringleaders.

Queen Isabella of Castile issues the Alhambra Decree, ordering her 150,000 Jewish and Muslim subjects to convert to Christianity or face expulsion.

On March 31, 1492, Queen Isabella issues the Alhambra Decree, forcing Spain’s Jews and Muslims to convert or be expelled.

Ferdinand Magellan and fifty of his men came ashore to present-day Limasawa to participate in the first Catholic mass in the Philippines.

In 1521, Ferdinand Magellan lands on Limasawa and celebrates the first recorded Catholic mass in the Philippines.

The Long Parliament presents the Humble Petition and Advice offering Oliver Cromwell the British throne, which he eventually declines.

In 1657, England’s Long Parliament proposes the Humble Petition and Advice to make Oliver Cromwell king, a title he ultimately refuses.

The last session of history of the Catalan Courts, the parliamentary body of the Principality of Catalonia, ends. Catalonia's constitutional modernisation passed by the Courts aims to improve the guarantee of individual, political and economic rights (among them, the secrecy of correspondence).

On March 31, 1706, the Catalan Courts meet for the final time, approving reforms to strengthen civil and economic rights.

A sermon on "The Nature of the Kingdom of Christ" by Benjamin Hoadly, the Bishop of Bangor, preached in the presence of King George I of Great Britain, provokes the Bangorian Controversy.

Bishop Benjamin Hoadly’s 1717 sermon before King George I sparks the Bangorian Controversy over church authority and state power.

The 1761 Lisbon earthquake strikes off the Iberian Peninsula with an estimated magnitude of 8.5, six years after another quake destroyed the city.

A powerful earthquake of estimated magnitude 8.5 shakes Lisbon’s coast in 1761, reopening wounds from the catastrophic 1755 tremor.