France: Henry VIII had longstanding conflicts with France over territory and power struggles in Europe. He invaded France several times, most notably in 1513 during the Battle of the Spurs and in 1520 during the Field of the Cloth of Gold.
Scotland: Henry VIII had a strained relationship with Scotland, often leading to military confrontations. One notable conflict was the Battle of Flodden Field in 1513, where the English forces won a decisive victory against the invading Scottish army.
Holy Roman Empire: Henry VIII's desire to annul his marriage to Catherine of Aragon led to a conflict with the Holy Roman Empire, ruled by her nephew, Emperor Charles V. The empire imposed economic sanctions on England, and there were concerns about potential military conflicts.
Papacy: Henry VIII's break with the Roman Catholic Church, known as the English Reformation, caused significant tension with the papacy. Pope Clement VII excommunicated Henry in 1533, which further strained relations between England and the Holy See.
Irish chieftains: Henry VIII faced rebellions and resistance from various Irish chieftains throughout his reign. He sought to consolidate English control over Ireland and implement the Tudor policies of surrender and regrant.
Ottoman Empire: Although not directly engaging in combat, Henry VIII had diplomatic relations with the Ottoman Empire and sought alliances with them against his European rivals.