Plovdiv reached an agreement that the Principality of Bulgaria and Eastern Rumelia had a common government, Parliament, administration, and army. Today 6 September is celebrated as the Unification Day and the Day of Plovdiv. After the unification, Plovdiv remained the second most populous city in Bulgaria after the capital Sofia. The first railway in the city was built in 1874 connecting it with the Ottoman capital, and in 1888, it was linked with Sofia. In 1892 Plovdiv became host of the First Bulgarian Fair with international participation which was succeeded by the International Fair Plovdiv. After the liberation, the first brewery
Plovdiv European mosque outside Moorish Spain. The Sephardic Plovdiv Synagogue is at Tsar Kaloyan Street 13 in the remnants of a small courtyard in what was once a large Jewish quarter. Dating to the 19th century, it is one of the best-preserved examples of the so-called "Ottoman-style" synagogues in the Balkans. According to author Ruth E. Gruber, the interior of the Plovdiv Synagogue is a "hidden treasure…a glorious, if run-down, burst of color." An exquisite Venetian glass chandelier hangs from the center of the ceiling, which has a richly painted dome. All surfaces are covered in elaborate, Moorish-style, geometric designs in