Considers the future of the main taxes of the 20th century, namely, income tax, social security contributions, consumption taxes, and property and capital taxes. Firstly the 20th century as a whole and taxation in the 21st century are reviewed. Then various aspects each of the main taxes are examined: the rationale of the tax and the form it takes, its share of revenue in total and GDP, and the main developments during the 20th century. Lastly the prospects for the 21st century are looked at.