page_title: Empire of Nicaea
section_title: Expansion
hierarchical_section_title: Empire of Nicaea / History / Expansion
caption_attribution_description: English: The Lefke Gate in Iznik, along the western ramparts of the city.
context_page_description: The Empire of Nicaea or the Nicene Empire is the conventional historiographic name for the largest of the three Byzantine Greek rump states founded by the aristocracy of the Byzantine Empire that fled after Constantinople was occupied by Western European and Venetian forces during the Fourth Crusade. Like the Empire of Trebizond and the Empire of Thessalonica, it claimed to be the continuation of the Roman Empire.
  Founded by the Laskaris family, it lasted from 1204 to 1261, when the Nicaeans restored the Byzantine Empire in Constantinople.
context_section_description: The accession of Vatatzes was initially challenged by the Laskarids, with the sebastokratores Isaac and Alexios, brothers of Theodore I, seeking the aid of the Latin Empire. Vatatzes prevailed over their combined forces, however, in the Battle of Poimanenon, securing his throne and regaining almost all of the Asian territories held by the Latin Empire in the process.
  In 1224, the Latin Kingdom of Thessalonica was captured by the Despot of Epirus Theodore Komnenos Doukas, who crowned himself emperor in rivalry to Vatatzes and established the Empire of Thessalonica. It proved short-lived, as it came under Bulgarian control after the Battle of Klokotnitsa in 1230. With Trebizond lacking any real power, Nicaea was the only Byzantine state left, and John III expanded his territory across the Aegean Sea. In 1235, he allied with Ivan Asen II of Bulgaria, allowing him to extend his influence over Thessalonica and Epirus.
  In 1242, the Mongols invaded Seljuk territory to the east of Nicaea, and although John III was worried they might attack him next, they ended up eliminating the Seljuk threat to Nicaea. In 1245, John allied with the Holy Roman Empire by marrying Constance II of Hohenstaufen, daughter of Frederick II. In 1246, John attacked Bulgaria and recovered most of Thrace and Macedonia, and proceeded to incorporate Thessalonica into his realm. By 1248, John had defeated the Bulgarians and surrounded the Latin Empire. He continued to take land from the Latins until his death in 1254.
  Theodore II Lascaris, John III's son, faced invasions from the Bulgarians in Thrace, but successfully defended the territory. A conflict between Nicaea and Epirus broke out in 1257. Epirus allied with Manfred of Sicily when Theodore II died in 1258. John IV Lascaris succeeded him, but as he was still a child he was under the regency of the general Michael Palaeologus. Michael proclaimed himself co-emperor (as Michael VIII) in 1259, and soon defeated a combined invasion by Manfred, the Despot of Epirus, and the Latin Prince of Achaea at the Battle of Pelagonia.
caption: Nicaea city wall, Lefke gate; Iznik, Turkey
exif: {"Image Make": "Panasonic", "Image Model": "DMC-LZ3", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "GIMP 2.4.2", "Image DateTime": "2008:09:01 19:05:05", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "420", "Image PrintIM": "[80, 114, 105, 110, 116, 73, 77, 0, 48, 50, 53, 48, 0, 0, 14, 0, 1, 0, 22, 0, ... ]", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "7058", "Thumbnail JPEGInterchangeFormatLength": "5873", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExposureTime": "1/160", "EXIF FNumber": "28/5", "EXIF ExposureProgram": "Program Normal", "EXIF ISOSpeedRatings": "80", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2008:08:30 11:48:53", "EXIF DateTimeDigitized": "2008:08:30 11:48:53", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "4", "EXIF ExposureBiasValue": "1", "EXIF MaxApertureValue": "3", "EXIF MeteringMode": "Pattern", "EXIF LightSource": "Unknown", "EXIF Flash": "Flash did not fire, compulsory flash mode", "EXIF FocalLength": "61/10", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "2560", "EXIF ExifImageLength": "1920", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "6910", "EXIF SensingMethod": "One-chip color area", "EXIF FileSource": "Digital Camera", "EXIF SceneType": "Directly Photographed", "EXIF CustomRendered": "Normal", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF DigitalZoomRatio": "0", "EXIF FocalLengthIn35mmFilm": "37", "EXIF SceneCaptureType": "Standard", "EXIF GainControl": "None", "EXIF Contrast": "Normal", "EXIF Saturation": "Normal", "EXIF Sharpness": "Normal"}