Timeline syntax

Begin with the timeline keyword so Mermaid knows you want a chronology diagram.

Add an optional title on the next line with title followed by the heading text.

Each data line starts with a time period, then a colon, then the event text.

Periods and events are plain text — not limited to years or numbers.

Put several events on one line with extra colons, or continue with lines that start with a colon under the same period.

Order matters: earlier events sit above later ones for that period.

Use section followed by a name to group following periods into an age or era.

A new section starts when you declare another section. Periods without a section use the default group.

Long period or event text wraps by default so it stays inside the diagram.

Force a break with <br> when you want a specific two-line label.

After timeline you can set direction: LR (left to right, default) or TD (top to bottom).

Use TD when a vertical chronology reads better for your layout.

Combine title, sections, periods, and multi-event lines into the examples template.