Today is Muharram—the tenth day of the first sacred month of the Islamic calendar—and the single most important festival for the Shia community. It is a time for prayer, reflection and mourning—as it also marks the anniversary of the battle of Karbala, where Prophet Muhammad's grandson Imam Hussain Ibn Ali was killed. The painting (circa 1800) above is titled ’Shi’a Muslims Mourning Before a Ta’ziya’—and is by an unknown European artist. You can see the others over at Heritage Lab–which has put together a lovely collection of paintings that commemorate the occasion. .