In modern times, a trademark can represent more than just the source of goods and services or quality, but also an idealized brand image that buyers want to have. Business owners have begun to invest in building a positive reputation for their brand through various forms of advertising. The original scope of trademark protection under Article 5 (1) (a) of the Trade Mark Directive (TMD) was limited to the origin and quality guarantee functions under the essential function theory. However, subsequent rulings by the Court of Justice of the European Union (CJEU) have broadened this scope to include communication, investment, and advertising functions, also known as "modern" functions, to protect trademark owners' investments. This enlargement has sparked ongoing discussions in European trademark law. The free movement of goods principle and the exercise of exclusive rights linked with trademarks have long been at odds with each other. The CJEU settled this dispute by establishing the concept of European exhaustion, which the TMD subsequently put into practice in Article 7 (1). However, this broad rule is not absolute, as a trademark owner with strong cause to oppose the continued marketing of products will not be exhausted. This thesis examines the effects of the TMD's enhancement of trademark protection under Article 5 (1) (a) on trademark owners' rights to resist wider marketing of their branded items in the context of parallel importation.