Corvo Attano, The Royal Protector In Our Times, Part 02 is a book found in Dishonored 2.
In an act of rebellion, young Jessamine Kaldwin chose Corvo as her Royal Protector when Corvo was 19 and she was 12. He served her loyally as a bodyguard, courier and some say spy, before and after she was crowned Empress. Though it was scandalous gossip at the time, it is said they began a love affair around 1823, when Jessamine was 18 and Corvo 25.
The next chapter of Attano's life is like something out of a legend.
During the Time of the Rat Plague, when the Empress fell, Corvo was accused of regicide and sentenced to execution. He was thrown into Coldridge Prison and publicly reviled. He escaped, and as part of a small conspiracy dedicated to throwing down the tyrannical Lord Regent, Corvo struck back at the people who killed the Empress and who wronged him. As the Lord Regent fell, the Loyalist conspiracy turned on Corvo, poisoning him. Surviving through some inner resilience, he located the true assassin of the Empress and fought his way out of the Flooded District. Corvo eventually cornered the last of the Loyalists on Kingsparrow Island, at the Burrows Lighthouse, and rescued Emily Kaldwin, heir to the throne.
The romantic involvement between Corvo Attano and the Empress Jessamine Kaldwin was a terribly-kept court secret, and thus it is widely held that Emily Kaldwin is their daughter. Following the interregnum, Corvo watched over Emily as she began to rule the Empire of the Isles.