July 18

On 18 July 1862, a mountaineering team achieved the first successful ascent of Dent Blanche, a 4,357-meter summit in the Swiss Alps. Dent Blanche is renowned for its steep ridges, ice fields and unpredictable weather, making it a formidable challenge. The climbers overcame technical rock and ice sections on the mountain's northeast ridge to reach the summit. Their pioneering route paved the way for future expeditions and contributed to the era known as the golden age of alpinism. Contemporary reports highlight the team's careful planning, use of early alpine gear and navigation skills. The ascent of Dent Blanche marked one of the last major unclimbed high peaks in the Alps. Today, Dent Blanche remains a coveted objective for skilled mountaineers worldwide.

On 18 July 1870, the First Vatican Council (1869–1870) promulgated Pastor Aeternus, its dogmatic constitution on the Church of Christ. The council declared that the Pope, when speaking ex cathedra on faith or morals, is preserved from error by divine assistance. The doctrine of papal infallibility was intended to strengthen papal authority amid church-state tensions in 19th-century Europe. Debate at the council had been intense, reflecting divisions between ultramontane and conciliarist theologians. The declaration was immediately controversial, eliciting both praise for clarity of doctrine and criticism for centralization of power. Shortly after the council's adjournment, the outbreak of the Franco-Prussian War delayed its final sessions. Today, papal infallibility remains a defining principle of Roman Catholic ecclesiology.

On July 18, 1984, James Oliver Huberty entered a McDonald’s restaurant in San Ysidro, California, armed with multiple weapons. He opened fire on customers and staff, killing 21 people and injuring 19 others in a devastating mass shooting. Police officers arrived on the scene and ultimately shot and killed Huberty outside the restaurant. The incident prompted national debates on gun control and mass shooting prevention measures. Survivors and the community marked the event as one of the worst mass murders in U.S. history at the time.

On July 18, 1994, a powerful car bomb detonated outside the Asociación Mutual Israelita Argentina in Buenos Aires. The explosion claimed the lives of 85 people, most of whom were Jewish community members, and wounded over 300. The attack shocked Argentina and remained the deadliest terrorist act in the country's history. International investigations pointed to foreign extremist networks, but accountability remained contested. The bombing prompted heightened security measures at Jewish and international institutions across South America.