Excel doesn't have a built-in chart type specifically for timelines. However, you can achieve a timeline visualization using a scatter chart with some customization:

Here's how to create a timeline chart in Excel:

1. Prepare your data:
- Organize your data in a table with three columns:
- Dates: This column should contain the dates for your events or data points in chronological order.
- Events/Values: This column lists the names or descriptions of your events or the data values you want to represent on the timeline.
- Order/Position: (Optional) This column can be used to define the vertical placement of events on the timeline (positive numbers above the axis, negative numbers below). If not used, all events will appear on the same level.

2. Create a scatter chart:
- Select your data table.
- Go to the "Insert" tab on the Excel ribbon.
- Click on the "Scatter" chart option within the "Charts" group.
- Choose a basic scatter chart type (e.g., Scatter with Markers).

3. Format the chart axes:
- Right-click on the horizontal (x) axis and select "Format Axis."
- Under "Axis Options," choose the date format that best suits your data (e.g., "d-mmm-yy" for day-month-year).
- Right-click on the vertical (y) axis (if you used an "Order/Position" column) and format it according to your numbering scheme. You can hide this axis if all events should be displayed at the same level.

4. Customize data markers:
- Right-click on any data marker (circle, square, etc.) and select "Format Data Series."
- Choose the marker fill and line color, size, and style that best represent your events.

5. Remove unnecessary chart elements:
- Click on the chart title and press "Delete" to remove it if you don't need it.
- You can also remove the legend or gridlines by right-clicking on them and selecting "Delete."

6. Add data labels (optional):
- Right-click on a data marker and select "Add Data Labels."
- Choose how you want to display the data labels (e.g., date only, event name only, or both).

Additional Tips:

- You can use different marker shapes or colors to distinguish between different event categories on your timeline.
- Consider adding trendlines to visualize overall trends in your data over time.
- If you have a large number of events, explore using a stacked scatter chart to group related events and avoid overlapping markers.

By following these steps and customizing the chart elements, you can create a clear and informative timeline visualization in Excel to showcase your data trends over time.