The phrase "until the twentieth century" refers to a time period that extends from ancient times up to and including the year 1900. This era encompasses significant historical developments, cultural shifts, and scientific advancements. Here are some key points about this period:

1. **Historical Periods**: The timeframe includes major historical periods such as the Middle Ages, the Renaissance, the Age of Enlightenment, and the Industrial Revolution.

2. **Technological Advancements**: Innovations like the steam engine, telegraph, and early forms of photography were introduced during this time.

3. **Political Changes**: Major political transformations occurred with the rise and fall of empires, revolutions, and the formation of modern nation-states.

4. **Cultural Developments**: Significant artistic movements like Baroque, Romanticism, and Realism flourished during this period.

5. **Scientific Discoveries**: Important scientific breakthroughs in fields like physics, chemistry, and biology laid the groundwork for modern science.

6. **Social Movements**: Various social reform movements aimed at improving working conditions, women's rights, and abolishing slavery gained momentum.

This era was marked by continuous progress and change, setting the stage for the rapid developments of the 20th century.