Albania holds two records that sit oddly together: it is the only country in Europe with a Muslim majority, and it is among the least religiously observant societies on the continent. Both are products of the same history.
The territory was Christian, divided between the Latin north and the Orthodox south along the old imperial line, and became largely Muslim under Ottoman rule over several centuries. Conversion here was unusually thorough and unusually shallow at the same time. It brought fiscal and legal advantages, it proceeded gradually, and it left a population where confessional boundaries ran through villages and sometimes through families, with a well documented practice of crypto Christianity and of households maintaining observances on both sides.
Out of that came a national self understanding, formulated during the nineteenth century awakening and usually summarised in Pashko Vasa's line that the religion of Albanians is Albanianism. The point of it was political: a people divided among three confessions could only assert itself as a nation if the confessions were subordinated to it. That formula was available for the communist state to weaponise later.
Sunni Islam is the largest affiliation, followed by Catholicism concentrated in the north around Shkoder and Orthodoxy in the south. Albania is also the world headquarters of the Bektashi order, a Sufi tradition with distinctive doctrine and a heterodox reputation, which relocated to Tirana in 1925 after the Turkish republic closed the tekkes. It is recognised in Albania as one of the four traditional religious communities, which gives it a status it holds nowhere else.