Before 1200

late 7th / early 8th century	Finds of human bones prove that the area around today's St. Michael's Church was used as a burial ground.
Between 780 and 802	Isserstedt is mentioned in a list of donations to the Fulda monastery as the first settlement belonging to the town today.
between 896 and 899	The place name "Iani" is mentioned in a tithe register of the Hersfeld monastery. The place name, derived from an Indo-European/Germanic root (roughly: "area at the river crossing"), most probably refers to present-day Jena, which lies on a ford of the Saale and is touched by traffic routes from the Erfurt area.
937	December 20: The royal castle "Chirihberg" ("Kirchberg") on the local hill east of Jena is mentioned. The eponymous church is the earliest mention of a place of worship in the Jena area.
974	June 20: Emperor Otto II stays on Kirchberg, which suggests the existence of a royal or imperial palace.
before 1100	The first predecessor of St. Michael's is built as a small Romanesque hall church.
around 1100	Construction of a second castle on the Hausberg (Kirchberg II), owned by the Wettin Margraves of Meissen, begins. The keep, a preserved structural remnant known as the "Fuchsturm", is one of the "seven wonders" of Jena.
1145	August 15: The naming of a Folmarus de Gene ("Volmar von Jena") as a witness in a document of the Archbishop of Mainz represents a second mention of Jena.
1149	November 30: The noble family of the Burgraves of Kirchberg is mentioned for the first time as administrators of the imperial property in Kirchberg.
around 1150	Construction of the oldest parts of the Romanesque St. John's Church begins (in the later suburb of Leutra).
1156	The noble family of the Greif(en)berger, which died out in 1257, is mentioned for the first time. A castle on the Hausberg at its western tip forms the center of their domain. The village of Lobeda is mentioned for the first time (uncertain).
1158	January 1: Jenzig ("montem genzege") and Gleissberg ("montem Glizberch") appearin a document by Frederick Barbarossa.
1166	The documentary mention of the brothers Hartmann and Otto von Lobdeburg (Lofdeburch) indicates the existence of Lobdeburg Castle as the new ancestral seat of the noble family (the "Lobdeburgers") who came to the middle Saale from Franconia. (An earlier mention around 1150 is also possible). The dynasty had a decisive influence on the history of Jena in the following 150 years.
Between 1175 and 1200	Five bracteates minted in Jena by the Lords of Lobdeburg have survived, proving that the Lobdeburgs were the lords of Jena.
1182	September 16: Zwätzen (first place name) is mentioned as a place located between Dornburg and Jena. The use of Jena as the place of reference indicates a prominent position compared to other settlements. The document contains the first reliable evidence of viticulture near Jena.
1185	Margrave Otto of Meissen grants the Altzelle monastery, among other things, a tithe from a vineyard on the Jenzig.
Around 1200	The settlement area of Jena is (re)built according to a foundation plan. A regular system of longitudinal and transverse lanes is created, which can still be partially traced in the city center today. The lords of Lobdeburg were the driving and organizing force. From the middle of the 13th century, the emerging town is divided up between various sub-lines of the Lobdeburgs, finally (1290) according to the four districts.