Complex sentence: Norreys continued his good service and was ordered by Leicester to protect Utrecht in August 1586, which didn't go smoothly because Leicester omitted to put Sir William Stanley under Norreys' command.
Split into simpler sentences: Norreys continued his good service and was ordered by Leicester to protect Utrecht in August 1586. The operation didn't go smoothly because Leicester had omitted to put Sir William Stanley under Norreys' command.