Here are some one liners...
The Statute of Frauds and the Power of a Handshake -- All transactions must now be in writing, with a signature and a date. I talk about agreements made with a handshake and one such modern deal that went wrong and then very right.
The Essentials of Enlightenment Philosophy -- Spinoza publishes his greatest philosophical work and then drops dead. I also talk about my personal prejudices toward his work.
Paris Just Became Cool and Terrible -- Ice cream becomes popular. I talk about cooling in the 17th century and then talk a lot about the recent terror attacks in Paris.