Rubuta ci gaba ga wannan sakin layi - Williams ya kasance a Ingila don taimakawa wajen yaki da Armada na Spain a 1588. Williams ya bi Sir Francis Drake a wannan tafiyar
zuwa Spain da Portugal a 1589, kuma daga baya ya yi yaƙi a madadin Huguenots na Faransa. Ya sadu da Earl na Essex a shekara ta 1589, kuma su biyu sun zama kusa da juna lokacin da Sarauniya Elizabeth ta tura su don jagorantar rundunar soja a matsayin abokan haɗin gwiwa na Henry na Navarre a kan Katolika na Katolika a lokacin da Mutanen Espanya suka mallaki Brittany a 1592. Ya ci gaba da bauta wa Henry a kan League a ƙarshen 1580s da 1590s, ya sami babban nasara a yakin Arques. Bayan Essex ya koma Ingila Williams ya zama babban kwamandan sojojin Ingila da ke tallafawa Henry da kuma "a zahiri" wakilin Sarauniya. Ba da daɗewa ba bayan haka ya kama Aumerle tare da mutane 600 kawai. A lokacin Siege na Rouen a 1592, ya kusan kashe shugaban Albania-Italiyanci Giorgio Basta a cikin yaƙi na sirri, ya yanke wuyansa kuma ya kore shi da mutanensa daga fagen. Waɗannan ayyukan sun sa Williams ya zama sanannen jarumi a Ingila, kuma an buga littattafai game da ayyukansa. Sir Henry Umton ya bayyana cewa Sarki Henry yana cike da yabo ga Williams da mutanensa, "Ban taɓa jin ya ba da girmamawa ga kowane sabis ba ko ga kowane mutum fiye da yadda yake yi wa Sir Roger Williams da sauran".