Ok I'll bite... it's important to learn British History when in the Uk to understand the following:
Formation of democracy
Migration of peoples and how they have added to modern times
Significant events that have shaped society and impact today
To learn the mistakes of the past.
To understand the atrocities of the Holocaust (only legally required topic)
To understand local history and impact on today.
To understand the spread and influence of religion and it's decline.
All of these elements are crucial to understanding modern society and current affairs. Events influence modern society from the Celts onwards (earlier really) and the national curriculum reflect this. Students learn in a chronological order in most schools again an important historical skill not taught in most subjects.
In addition to this vital life skills of debate, using evidence, putting forward an argument, understanding the usefulness of evidence, cause and consequence, long and short term impacts, extended writing, understanding interpretations and their origins, analysis, evaluation, synthesis. All of which are critical work place skills and enables students to access further and higher education.
As for you examples every single one is covered by most schools. Other examples include: LGBTQ rights, civil rights, Cold War, in depth studies of particular decades/ countries.
History is definitely not just about acquiring knowledge, it's about being able to acquire key skills, understand the world and how history links to modern affairs and local history too.
It's definitely not about irrelevant content, pub quiz facts, dates and Henry's wives!!!!!