World War I: Allied troops <a href="https://en.wikipedia.org/wiki/Battle_of_Dobro_Pole" id="mwsw" rel="mw:WikiLink" title="Battle of Dobro Pole">break through</a> the <a href="https://en.wikipedia.org/wiki/Kingdom_of_Bulgaria" id="mwtA" rel="mw:WikiLink" title="Kingdom of Bulgaria">Bulgarian</a> defenses on the <a href="https://en.wikipedia.org/wiki/Macedonian_front" id="mwtQ" rel="mw:WikiLink" title="Macedonian front">Macedonian front</a>.