http://revach.net/article.php?id=3589

Section: Hanhagos   Category: Ma'aseh Rav
Mazal Tov To Kaiser Wilhelm! - Rav Yaakov Tzvi Mecklenberg
Rav Yaakov Tzvi Mecklenberg was a talmid of Rebbi Akiva Eiger and the author of the renowned H'Ksav V'Hakabala on Chumash.  He was the Rav of Kennigsberg in Germany and apparently fearless as the following story suggests.

The Rav, Rav Yaakov Tzvi was invited to officiate at the wedding of a girl from a liberal home.  The girl refused to follow the requirements necessary for a Bas Yisroel to prepare for her wedding.  Because of this Rav Yaakov Tzvi refused to officiate at the wedding.  However with pressure from the government, Rav Yaakov Tzvi was forced to do so and finally relented.

Rav Yaakov Tzvi stood under the Chupah and said to the Choson for him to repeat to the Kallah the standard language of kedushin, "Harei At Mikudeshes Li" you are married to me.  Then he continued and instead of saying, "K'Das Moshe V'Yisroel", Rav Yaakov Tzvi said, "K'Das Kaiser Wilhelm the Great!"  An uproar ensued as the befuddled Mechutanim demanded that he explain why he did not say "K'Das Moshe V'Yisroel".  He calmly explained that this wedding was not "K'Das Moshe V'Yisroel" since according to Toras Moshe a kallah must prepare herself in the Jewish way.  This wedding and his presence was purely on the say so of the Kaiser so he made sure to use the correct and appropriate words attributing the wedding vows to whom they in fact belonged.

Rav Yaakov Tzvi held his position and refused to budge.  Without any other options the wedding was cancelled and held at a later date after the girl made all the proper preparations... and Rav Yaakov Tzvi proudly officiated the Chasuna "K'Das Moshe V'Yisroel". Yehi Zicro Boruch!