lord mountjoy was a kinsman of robert devereux, 2nd earl of essex both by blood and by marriage to his sister penelope. this gained his cousin the earl's patronage. charles accompanied the earl of essex on a successful expedition to capture cadiz in june 1596, after which he was knighted (probably one among the large number essex knighted on board ship before returning to england - so many that the queen complained), and to ireland in 1599 (becoming "coronell governor" of cahir castle in tipperary.