The Reconquista (Portuguese and Spanish for "reconquest") was the period in the history of the Iberian Peninsula of about 780 years between the Umayyad conquest of Hispania in 711 and the fall of the Nasrid kingdom of Granada to the expanding Christian kingdoms in 1492. The beginning of the Reconquista is traditionally marked with the Battle of Covadonga (718 or 722), the first known victory in Hispania by Christian military forces since the 711 military invasion undertaken by combined Arab-Berber forces. In that small battle, a group led by the nobleman Pelagius defeated a Muslim patrol in the mountains of northern Iberia and established the independent Christian Kingdom of Asturias. In the late 10th century, the Umayyad vizier Almanzor waged military campaigns for 30 years to subjugate the northern Christian kingdoms. His armies, mostly composed of Slavic and African Mamluks (slave soldiers), ravaged the north, even sacking the great shrine of Santiago de Compostela. When the government of Córdoba disintegrated in the early 11th century, a series of petty successor states known as taifas emerged. The northern kingdoms took advantage of this situation and struck deep into Al-Andalus; they fostered civil war, intimidated the weakened taifas, and made them pay large tributes (parias) for protection. After a Muslim resurgence in the 12th century the great Moorish strongholds in the south fell to Christian forces in the 13th century—Córdoba in 1236 and Seville in 1248—leaving only the Muslim enclave of Granada as a tributary state in the south. After 1491, the entire peninsula was controlled by Christian rulers. The conquest was followed by the Alhambra Decree (1492) which expelled Jews who would not convert to Christianity from Castile and Aragon, and a series of edicts (1499–1526) which forced the conversions of the Muslims in Spain, although later a significant part of them were expelled from the Iberian Peninsula. Traditional historiography uses the term Reconquista starting at 19th century for what was earlier thought as a restoration of the Visigothic Kingdom over conquered territories. The concept of Reconquista, consolidated in Spanish historiography in the second half of the 19th century, was associated with the development of a Spanish national identity, emphasizing nationalistic and romantic, and occasionally, colonialist, aspects.

Dragutin Keserović (Serbian Cyrillic: Драгутин Кесеровић; 21 November 1896 – 17 August 1945) was a Serbian Chetnik military commander holding the rank of lieutenant colonel and vojvoda during World War II. Keserović was probably the most active commander of Mihailović's Chetniks in Serbia. Immediately after the Axis invasion of Yugoslavia in April 1941, then Major Keserović joined the Pećanac Chetniks of World War I voivode Kosta Pećanac. In August, Pećanac concluded a collaborationist agreement with the Germans. Keserović transferred to the Chetniks of Draža Mihailović when he heard of Mihailović. On 24 September, Keserović's Chetnik detachment attacked German troops in the Kruševac district, killing 23 soldiers. In January 1943, Axis forces launched Case White, a combined strategic offensive aimed at destroying the Yugoslav Partisan resistance in the neighbouring Independent State of Croatia. Two corps of Chetniks were sent from occupied Serbia to support Chetnik formations that had participated on the Axis side in the offensive and been defeated by the Partisans following the latter's crossing of the Neretva River. These corps were led by Keserović and , and totalled 2,000 men. By early May, the two corps were deployed in the area of Bijelo Polje in the Italian governorate of Montenegro, but Mihailović became aware of the German intention to capture him, and decided to return to occupied Serbia. In 1943 the British sub-mission was established in the headquarter of Keserović. According to Chetnik officer Milan Deroc, the name of the British Liaison Officer (BLO) at Keserovićs HQ was Major Bob Wade Shortly before Italian capitulation in September 1943, Keserović raided two German railway transports and shifted back German attacks to Mihailović headquarters. According to the German Foreign Office representative for the Balkans, Hermann Neubacher, Keserović concluded a formal "armistice agreement" with the Germans in his area of operations in the German-occupied territory of Serbia in late 1943. Such agreements were negotiated by at least four other senior Chetnik commanders in the occupied territory at this time. These agreements ensured that the Chetniks in these areas were safe from the Germans while they continued to fight the Partisans, they were provided with limited ammunition by the Germans, were provided with medical assistance, including having their wounded treated in German hospitals, they were allowed freedom of movement, and the ability to forcibly recruit manpower in their areas of responsibility. On 30 November 1943 Keserović sent report to Mihailović with information that Germans offered him cooperation, arms and ammunition, which he refused and denied all news about any connection with Germans. In late August 1944, a US Office of Strategic Services mission led by Colonel Robert H. McDowell was parachuted into a Chetnik-controlled area of occupied Serbia to join Mihailović's headquarters, gather general intelligence and establish contacts with representatives of pro-Western forces in Hungary, Bulgaria and Romania. One member of the mission was Lieutenant Ellsworth Kramer. Kramer was quickly detached to Keserovic. Due to the fact that the situation of the Chetniks seriously deteriorated soon after the mission's arrival, most of McDowell's time was dedicated to the problems faced by the Chetniks, and little if any contact with potential allies in neighbouring countries was undertaken.