The oldest Republican tricolour in the world, the Prinsenvlag (orange-white-blue) was introduced in the struggle against the Spanish under leadership of the Prince of Oranje Nassau in 1579. The red-white-blue version was officially established on 14 February 1796, supposedly because ''the colour red was better visible at sea''. The flag inspired the revolutionary flag of France and the flag of Russia under Czar Peter the Great in the 18th Century. Orange (for the House of Orange) has remained the National Colour.