Angels in Iron is the absorbing tale of the siege of Malta in 1564 between the Knights of St. John of the Hospital (a military religious order) and Suleiman's forces. Suleiman, the most famous sultan of the Turkish Ottoman Empire (who has at this point significantly expanded his empire) has grand plans to conquer the world - and that includes Malta, the new home of the Knights of St. John of the Hospital. The Grand Master of this order witnessed their surrender at Rhodes (their former home) when he was a young knight. Now he is determined to hold on to Malta to the bitter end.