Rafael Sabatini 
St. Martin’s Summer 

The life of an heiress is in jeopardy and her only hope is to place her trust in the wiles of a middle-aged swordsman with no use for "women’s troubles." As the plots of the conspirators converge it will take all the wiles and accumulated wisdom of Martin Marie Rigobert de Garnache to uncover their identity, to save Valerie de La Vauvraye and keep his promise to his Queen. A great swashbuckler with a fun romance plot. Some of the twists of the plot are a bit obvious, but Sabatini makes them work nevertheless. There’s enough action to please action fans and enough romance to please romance fans. (Goodreads)