The theme answers consist of the Electors of the HOLY ROMAN EMPIRE (as generally and commonly rendered in English). The original seven, established by the Golden Bull of 1356, were the archbishops of COLOGNE, MAINZ, and TRIER, the king of BOHEMIA, the margrave of BRANDENBURG, the count Palatine of the Rhine, possessor of the PALATINATE, and the duke of SAXONY.
The Wittelsbachs of BAVARIA took the vote away from their cousins in the Palatinate in 1623, which was compensated with the eighth electorate in 1648. HANOVER was granted a vote in 1693, and exercised that vote in 1708 (when, coincidentally, Bohemia revived the use of its long-dormant vote). The PALATINATE expired completely in 1777 (and was ultimately united with Bavaria).
With the French annexation of the left bank of the Rhine at the turn of the nineteenth century, the bishoprics of Cologne and Trier were dissolved, while the vote of Mainz was transferred to RATISBON (Regensburg). These changes were ratified by the Final Act of 1803, which also created new votes for BADEN, HESSE-KASSEL, SALZBURG, and WÜRTTEMBERG. But the Grand Duke of Tuscany, then in possession of Salzburg, exchanged it for WÜRZBURG two years later. All of this proved to be quite pointless, as the Holy Roman Empire finally expired in 1806. Despite having nothing to vote for, the rulers of Hesse-Kassel retained the title of Elector until the Prussian annexation of 1866.
11 COLOGNE [as in eau de cologne]
25 MA(IN)Ze
43 TRIER [judge or juror]
5 BO(HEMI)A
6 B(RAND)EN + BURG
29 PAL(A + TIN) ATE
38 S(AXON)Y
3 Be(AVA)RIA [Gardner homophone]
20 HAN + OVER
32 RATISBON [no b sitar reversal]
2 BADEN [half of Baden-Baden]
21-24 HESSE-KASSEL [she seeks las anagram]
36 7 SALZ + BURG [salts homophone]
45 W + fÜR + TT + EM + BERG [For in German: für; Mountain: Berg]
46 WÜR + Z + B + UR + G