Final answer:
Sir Walter Raleigh disobeyed King James I in 1618 by attacking the Spanish, which was part of the ongoing conflict between Protestant England and Catholic Spain during that era.
Step-by-step explanation:
The man who disobeyed King James I and attacked the Spanish in 1618 was Sir Walter Raleigh. Elizabethan privateers such as Sir Walter Raleigh and Sir Francis Drake were essentially state-sponsored pirates who attacked Spanish ships, contributing to the wealth of England. Both men were deeply involved in the tensions between Protestant England and Catholic Spain, at a time when religious animosity influenced political and military conflicts. While Sir Francis Drake was knighted by Queen Elizabeth I for his successful piratical ventures in the 1580s, it was Raleigh who in 1618, long after Elizabeth's reign, directly disobeyed James I by attacking the Spanish, an act which contributed directly to his eventual execution.