Avodah Zarah 11 - Other Roman Festivals
It is prohibited to trade with idolaters for three days before the emperor's birthday and the day of his death. The Sages limit this only to a case where his death was accompanied by the burning of his personal belongings
It is also forbidden to do business with a pagan on the day he shaves his beard and the lock of his hair - which were often grown for a year and then dedicated to the pagan's deity.
There was also another festival in Rome. Once in seventy years they would take a healthy person - representing Esau - and have him ride upon the shoulders of a lame person, representing Jacob. They would dress the upper man in the attire of Adam, the first man, which he had used for hunting, and they would put the scalp of Rabbi Ishmael on his head. They would declare, "The calculations of the ruler (Jacob) are wrong," (which meant that the Jews still have not been redeemed). The brother (Jacob) of our lord (Esau) is a cheat; woe to one of them when the other one arises."
Said Rav Ashi, "Their language made them stumble, since this can be understood as 'Our lord is a cheat.'"
Art: William Blake - Tiriel, borne back to the Palace on the Shoulders of his Brother Ijim, addressing his five Daughters