Sometimes not only church interiors but facades were also decorated with mosaics in Italy like in the case of the St Mark's Basilica in Venice (mainly from the 17th19th centuries, but the oldest one from 127075, "The burial of St Mark in the first basilica"), the Cathedral of Orvieto (golden Gothic mosaics from the 14th century, many times redone) and the Basilica di San Frediano in Lucca (huge, striking golden mosaic representing the Ascension of Christ with the apostles below, designed by Berlinghiero Berlinghieri in the 13th century). The Cathedral of Spoleto is also decorated on the upper facade with a huge mosaic portraying the Blessing Christ (signed by one Solsternus from 1207).
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When was the latest addition to the facade at St Mark's Basilica in Venice?
Ah, so.. from 127075

Like in English, Dutch has generalised the dative over the accusative case for all pronouns, e.g. Du me, je, Eng me, you, vs. Germ mich/mir dich/dir. There is one exception: the standard language prescribes that in the third person plural, hen is to be used for the direct object, and hun for the indirect object. This distinction was artificially introduced in the 17th century by grammarians, and is largely ignored in spoken language and not well understood by Dutch speakers. Consequently, the third person plural forms hun and hen are interchangeable in normal usage, with hun being more common. The shared unstressed form ze is also often used as both direct and indirect objects and is a useful avoidance strategy when people are unsure which form to use.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): When did the grammarians first draw the line between third person plural pronouns for Dutch?
Ah, so.. 17th century

Ancient tables provided the sun's mean longitude. Christopher Clavius, the architect of the Gregorian calendar, noted that the tables agreed neither on the time when the sun passed through the vernal equinox nor on the length of the mean tropical year. Tycho Brahe also noticed discrepancies. The Gregorian leap year rule (97 leap years in 400 years) was put forward by Petrus Pitatus of Verona in 1560. He noted that it is consistent with the tropical year of the Alfonsine tables and with the mean tropical year of Copernicus (De revolutionibus) and Reinhold (Prutenic tables). The three mean tropical years in Babylonian sexagesimals as the excess over 365 days (the way they would have been extracted from the tables of mean longitude) were 14,33,9,57 (Alphonsine), 14,33,11,12 (Copernicus) and 14,33,9,24 (Reinhold). All values are the same to two places (14:33) and this is also the mean length of the Gregorian year. Thus Pitatus' solution would have commended itself to the astronomers.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): Who was the architect of the Gregorian calendar?
Ah, so..
Christopher Clavius