Why is "World War II in Yugoslav Macedonia" trending?

Wikipedia Overview

World War II in Yugoslav Macedonia started with the Axis invasion of Yugoslavia in April 1941. Under the pressure of the Yugoslav Partisan movement, part of the Macedonian communists began in October 1941 a political and military campaign to resist the occupation of Vardar Macedonia. Officially, the area was called then Vardar Banovina, because the use of very name Macedonia was avoided in the Kingdom of Yugoslavia. Most of its territory was occupied by Bulgaria, while its westernmost part was ceded to Albania, both aided by German and Italian troops. Initially, there was no organised resistance in the region because the majority of the Macedonian Slavs nurtured strong pro-Bulgarian sentiments, although this was an effect from the previous repressive
Kingdom of Yugoslavia rule which had negative impact on the majority of the population. Even the local Communists, separated from the Yugoslav and joined the Bulgarian Communist Party. However, even those Macedonians who felt that they were Bulgarians soon discovered that the Bulgarians from Bulgaria were suspicious of them and considered them "backward Bulgarians" or second-class Bulgarians. In fact, Bulgarian authorities began a process of oppressive Bulgarianization as they realised that only part of the Macedonian population felt Bulgarian or was pro-Bulgarian. The occupation troops acted just as viciously and arrogantly toward the local population as did the officials. Thus, they soon became an object of disgust from the population, especially the great majority that felt themselves Macedonians developed strong resentment towards the Bulgarian regime as it acted the same way as the Serbian one before.