What did the Ilbert Bill controversy during Lord Lytton's time relate to?

As of 1883, when the Ilbert Bill was introduced, the Europeans could not be tried in court by Indian native judges.

Lord Ripon realised that this provision needed to be changed. So, the original Ilbert Bill allowed equal treatment for Europeans I.e. Indian judges could preside over cases involving Europeans.

This led to organised lobbying and opposition by all Europeans in India, and an amendment was brought as a compromise. As per amendment- Indian judges could preside over cases involving Europeans BUT the Europeans got right to demand trial by jury, where at least half of the jury would be White Europeans.

This completely defeated the purpose of the original Ilbert Bill. Though the educated Indians had also protested against the amendments, but they realised that to pressurise the government, all India organisation and more coordination amongst Indians to press for equal treatment. This is why Ilbert Bill controversy is seen as an important precursor to the formation of the INC.