The Battle of Lule Burgas (Turkish: Lüleburgaz Muharebesi) or Battle of Luleburgas – Bunarhisar (Bulgarian: Битка при Люлебургас – Бунархисар, Turkish: Lüleburgaz – Pınarhisar Muharebesi) was a battle between the Kingdom of Bulgaria and the Ottoman Empire and was the bloodiest battle of the First Balkan War. The battle took place from 28 October to 2 November 1912. The outnumbered Bulgarian forces made the Ottomans retreat to Çatalca line, 30 km from the Ottoman capital Constantinople.