Explanation:

- The sentence discusses the commander renouncing or giving up something he previously held towards the king.

- Option 1: regulation - Regulation refers to a rule or directive. It doesn't fit the context of personal loyalty or commitment.

- Option 2: reliance - Reliance indicates dependency or trust. It's not something typically renounced or abjured in this context.

- Option 3: sequence - Sequence means an order or series. It's unrelated to loyalty or allegiance.

- Option 4: allegiance - Allegiance is loyalty or commitment to a leader or cause. This fits perfectly in the context as something that can be renounced or abjured.

Option 4: allegiance is the correct choice. .