A Farewell to Arms primarily takes place during World War I in Italy along the Slovenian border, between the years 1916 and 1918. Although the protagonist, Frederic Henry, is an American, he fights for the Italian army as a lieutenant in the war, driving ambulances to battle sites in the countryside.
The novel moves between several cities, following Henry's participation in the war and his love story with Catherine. Initially, the reader finds Henry in Gorizia, a city bordering Slovenia, which serves as a safe haven for the Italian soldiers in the novel. In Gorizia, Henry socializes and drinks with his comrades like Rinaldi and acquaintances like the priest. Later in the novel, Henry and the ambulance drivers under his command travel to Pavla. At that battle site the drivers get hit by a mortar shell, killing some and badly wounding Henry's leg. After the explosion, Henry is sent to Milan to convalesce in an American hospital. In Milan, Henry and Catherine also solidify their relationship and begin to genuinely fall in love.
Despite Henry's purported attempts to avoid the front after his time in Milan, he is sent to Bainsizza, an area with heavy fighting. During the chaos and mistaken violence of the Italian army's retreat, Henry escapes to Stresa, where he reunites with Catherine again. At the end of the novel, Henry and Catherine escape to Switzerland, residing in both Montreux and Lausanne for the remainder of Catherine's pregnancy. Switzerland serves as a safe haven for many involved in World War I due to its political neutrality.