After 539 Ravenna was reconquered by the Romans in the form of the Eastern Roman Empire (Byzantine Empire) and became the seat of the Exarchate of Ravenna. The greatest development of Christian mosaics unfolded in the second half of the 6th century. Outstanding examples of Byzantine mosaic art are the later phase mosaics in the Basilica of San Vitale and Basilica of Sant'Apollinare Nuovo. The mosaic depicting Emperor Saint Justinian I and Empress Theodora in the Basilica of San Vitale were executed shortly after the Byzantine conquest. The mosaics of the Basilica of Sant'Apollinare in Classe were made around 549. The anti-Arian theme is obvious in the apse mosaic of San Michele in Affricisco, executed in 545547 (largely destroyed; the remains in Berlin).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When were the mosaics at the Basilica of Sant'Apollinare created?
Ah, so.. 549

Many historical sites exist throughout the city, including 59 properties listed on the National Register of Historic Places. Of these, nine are among the 60 U.S. National Historic Landmarks in Connecticut. The New Haven Green, one of the National Historic Landmarks, was formed in 1638, and is home to three 19th-century churches. Below one of the churches (referred to as the Center Church on-the-Green) lies a 17th-century crypt, which is open to visitors. Some of the more famous burials include the first wife of Benedict Arnold and the aunt and grandmother of President Rutherford B. Hayes; Hayes visited the crypt while President in 1880. The Old Campus of Yale University is located next to the Green, and includes Connecticut Hall, Yale's oldest building and a National Historic Landmark. The Hillhouse Avenue area, which is listed on the National Register of Historic Places and is also a part of Yale's campus, has been called a walkable museum, due to its 19th-century mansions and street scape; Charles Dickens is said to have called Hillhouse Avenue "the most beautiful street in America" when visiting the city in 1868.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): In 1868, which famous author is reported to have declared New Haven's Hillhouse Avenue to be "the most beautiful street in America?"
Ah, so.. Charles Dickens

In 1952, following a referendum, Baden, Wurttemberg-Baden, and Wurttemberg-Hohenzollern merged into Baden-Wurttemberg. In 1957, the Saar Protectorate rejoined the Federal Republic as the Saarland. German reunification in 1990, in which the German Democratic Republic (East Germany) ascended into the Federal Republic, resulted in the addition of the re-established eastern states of Brandenburg, Mecklenburg-West Pomerania (in German Mecklenburg-Vorpommern), Saxony (Sachsen), Saxony-Anhalt (Sachsen-Anhalt), and Thuringia (Thuringen), as well as the reunification of West and East Berlin into Berlin and its establishment as a full and equal state. A regional referendum in 1996 to merge Berlin with surrounding Brandenburg as "Berlin-Brandenburg" failed to reach the necessary majority vote in Brandenburg, while a majority of Berliners voted in favour of the merger.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What did the Baden Protectorate rejoin in 1990?
Ah, so..
unanswerable