Abrogate & Arrogate

Abrogate means ‘to repeal, annul or cancel’ and is used with reference to laws, treaties, and other formal agreements. For example: The dictator abrogated agreements that no longer suited his purposes.
Arrogate means ‘to lay claim to without justification’. For example: The general arrogated all civilian authority to himself, He arrogated to the prince several inflammatory statements, each suitable as a basis for opening hostilities.