What name, taken from a medieval fortress near London, was adopted in 1917 as the official name of the British royal family?

Introduction / Context:
The history of the British royal family includes a significant name change during the First World War, when anti German sentiment led the monarchy to drop its German sounding dynastic title. Instead, the royal house adopted a new name drawn from a famous castle not far from London. General knowledge questions frequently ask for this name, because it connects political history, geography, and symbolism.

Given Data / Assumptions:
• The change took place in 1917. • The new name was taken from a medieval fortress near London. • It became the official name of the British royal family. • Options list Windsor, Balmoral, Sandringham, Kensington, and Buckingham.

Concept / Approach:
Before 1917, the British royal family belonged to the House of Saxe Coburg and Gotha, reflecting its German connections through Queen Victoria and Prince Albert. During World War One, King George V decided to change the family name to reduce German associations. He chose Windsor, after Windsor Castle in Berkshire, which had long been a royal residence and symbol of the monarchy. From that point onward, the royal house has been officially known as the House of Windsor. The other place names in the options refer to royal estates or palaces but were not adopted as the family name.

Step-by-Step Solution:
Step 1: Note the key clues medieval fortress near London and new official name of the royal family in 1917. Step 2: Recall that Windsor Castle, west of London, is one of the oldest inhabited castles and a major royal residence. Step 3: Remember that the royal family changed its house name from Saxe Coburg and Gotha to Windsor during the First World War. Step 4: Check the options and find Windsor as a direct match to both the fortress and the adopted family name. Step 5: Choose Windsor as the correct answer.

Verification / Alternative check:
Historical records and the official royal website explain that on 17 July 1917 King George V issued a royal proclamation changing the name of the royal house from Saxe Coburg and Gotha to Windsor. They state that the new name was derived from Windsor Castle, a medieval fortress and royal residence in Berkshire. The House of Windsor remains the official name of the royal family today. No similar documentation exists for Balmoral, Sandringham, Kensington, or Buckingham being adopted as the dynastic name, which confirms that Windsor is correct.

Why Other Options Are Wrong:
• Balmoral is a royal estate in Scotland, used as a private residence, but it was never adopted as the family name. • Sandringham is a royal estate in Norfolk and likewise did not become the official dynastic title. • Kensington generally refers to Kensington Palace in London, a royal residence but not the basis for the house name. • Buckingham relates to Buckingham Palace, the monarch's official London residence, but the royal family did not take Buckingham as its surname or dynastic title.

Common Pitfalls:
• Confusing the main working palace, Buckingham Palace, with the dynastic name of the royal house. • Thinking any prominent estate like Balmoral or Sandringham might have been chosen without recalling the specific historical decision. • Forgetting that Windsor is both a castle and the official name of the royal house.

Final Answer:
The name taken from a medieval fortress near London and adopted in 1917 as the official name of the British royal family is Windsor.