Esseg, or Eszek (Slav. Oszek, anc. Mursia or Mursa), the capital of Slavonia, and one of the most strongly fortified towns in the Austrian dominions, is situated on the right bank of the Drave, 13 miles from its confluence with the Danube. Mursia was founded by the Emperor Hadrian in A.D. 125, and became afterwards the residence of the Roman governors of Lower Pannonia. It was erected into a bishopric by Constantine in 335. The present fortress was erected, upon the site of a previous one, by the Emperor Leopold I., between 1712 and 1719. It is not extensive, but is well constructed, containing many massive buildings, including an arsenal, and barracks capable of accommodating 30,000 men. It is surrounded by a broad esplanade, and is strengthened by works on the opposite side of the river. To the N.W. of it stands the Ober Varos, or Upper Town, with which it communicates by an avenue 1100 paces long. On the E. is the Unter Varos, or Lower Town, occupying the site of the ancient Mursia; while on the W. is the New Town. Esseck has 1 Greek and 5 Roman Catholic churches, 4 chapels, town-house, county hall, Catholic gymnasium, a High and a Greek school, and several monasteries. A long wooden bridge crosses the Drave and the swampy ground on the opposite side of that river. Pop. about 12,500, chiefly employed in the spinning of silk. Esseck is a steam-packet station, and a place of considerable trade in corn, cattle, and raw hides.