This visualization displays the reigns of British monarchs from 1066 to 2024 as a bubble chart, with each circle representing a monarch positioned along a timeline and colored according to their royal house (Windsor, Hanover, Stuart, etc.). The chart uses D3 v7’s `scaleLinear`, `axisBottom`, and `axisLeft` to construct the axes and `selectAll` with `enter().append('circle')` to render the SVG bubbles from a hardcoded data array containing monarch names, reign dates, and house affiliations.