Székely (sā´kəlē), ethnic group of Transylvania and of present-day Romania. Except in a few isolated communities, where the ancient customs of the Székely have survived, there is little difference between Székely and Magyars. The Székely (also known as Szeklers or Siculi) came into Transylvania either with or before the Magyars. Their organization was of the Turkic type, and they are probably of Turkic (possibly Avar) stock. By the 11th cent., however, they had adopted Magyar speech. They later formed one of three privileged nations of Transylvania (the others were the Magyars and the Saxons). With their own military and civil organization, they enjoyed autonomy under the Hungarian crown and were, without exception, regarded as of noble birth; they were exempt from taxation. In the 16th cent. the majority of the Székely accepted Calvinism as their religion, while some became Unitarians or remained Roman Catholics. Their privileges declined in the 18th cent. under the rule of Maria Theresa and Joseph II. The Austrian attempt to impress the Székely into service as a border militia met with widespread resistance. In 1763 a large number of Székely who sought to escape the Austrian recruiting agents were massacred at Madefalva. Many subsequently emigrated to Bukovina and Moldavia. The last remnants of Székely autonomy were suppressed by Austria after the Revolution of 1848. In post-cold-war Romania, where the Székely form roughly a third of the ethnic Hungarian population, members of the group have been among the most vocal Hungarians seeking an autonomous Hungarian region in Transylvania.