The following is the Bulgarian Order of Battle at the start of the Second Balkan War as of 29 June [ O.S. 16 June] 1913. This order of battle includes all combat units, including engineer and artillery units, but not medical, supply, signal, border guard and garrison units.
The Second Balkan War was a conflict which broke out when Bulgaria, dissatisfied with its share of the spoils of the First Balkan War, attacked its former allies, Serbia and Greece, on 16 (O.S.) / 29 (N.S.) June 1913. Serbian and Greek armies repulsed the Bulgarian offensive and counter-attacked, entering Bulgaria. With Bulgaria also having previously engaged in territorial disputes with Romania, this war provoked Romanian intervention against Bulgaria. The Ottoman Empire also took advantage of the situation to regain some lost territories from the previous war. When Romanian troops approached the capital Sofia, Bulgaria asked for an armistice, resulting in the Treaty of Bucharest, in which Bulgaria had to cede portions of its First Balkan War gains to Serbia, Greece and Romania. In the Treaty of Constantinople, it lost Edirne to the Ottomans.
Old Style (O.S.) and New Style (N.S.) are terms sometimes used with dates to indicate that the calendar convention used at the time described is different from that in use at the time the document was being written. There were two calendar changes in Great Britain and its colonies, which may sometimes complicate matters: the first was to change the start of the year from Lady Day to 1 January; the second was to discard the Julian calendar in favour of the Gregorian calendar. Closely related is the custom of dual dating, where writers gave two consecutive years to reflect differences in the starting date of the year, or to include both the Julian and Gregorian dates.
In modern use, the order of battle of an armed force participating in a military operation or campaign shows the hierarchical organization, command structure, strength, disposition of personnel, and equipment of units and formations of the armed force. Various abbreviations are in use, including OOB, O/B, or OB, while ORBAT remains the most common in the United Kingdom. An order of battle should be distinguished from a table of organisation, which is the intended composition of a given unit or formation according to the military doctrine of its armed force. As combat operations develop during a campaign, orders of battle may be revised and altered in response to the military needs and challenges. Also the known details of an order of battle may change during the course of executing the commanders' after action reports and/or other accounting methods as combat assessment is conducted.
