Currently in Europe, questions of patent infringement and validity are resolved at the national level, in the individual countries involved. This often requires parallel proceedings in the different countries, which is expensive and can yield inconsistent judgements and remedies.
The unified patent court (UPC) seeks to address this, providing a forum for the adjudication of patent disputes whose decisions are binding in the member states. Germany, the last of the three states whose approval is required, finally ratified the agreement in December of last year, and the UPC will go into effect in 2022.
Notably, however, due to Brexit, Great Britain, will not be party to the UPC, even though it had been one of the three required ratifiers (France was the other) before Brexit was a factor. As a result, patent disputes in Great Britain will need to be adjudicated in that country, in parallel with any proceedings in the UPC.
Sources: Attached Iam article “What you need to know about Brexit and Patents” https://www.iam-media.com/law-policy/patent-brexit-changes
Towards a Better Patent System for Europe: The Unified Patent Court (UPC) https://www.lexology.com/library/detail.aspx?g=6f95116d-1070-4dde-b53f-f31dcaf8504c