He was a great friend of Wolfe Tone who he had first met in the visitors gallery in Ireland's House of Commons in the year 1790. He was a founding member of the Society of United Irishmen that aimed to secure Civil & Political Liberties for the Irish People.
In 1795 Russell, Wolfe Tone, Henry Joy McCracken and Samuel Neilson led a band of United Irishmen to the top of Cave Hill overlooking the town of Belfast where they swore an oath:
"never to desist in our effort until we had subverted the authority of England over our country and asserted her independence"
In 1796 he was arrested and held without Trial until 1802 when England and France signed the brief Peace of Amiens. He was released on condition he went into Exile. He made his way to Paris where he met Emmet and he agreed to try and raise the North. He returned from exile in France specifically to help stir the North into Revolt in conjunction with Emmet’s Rising in Dublin, but he found that the spirit of ’98 was no longer there.
After Emmet's abortive Rising in Dublin he went on the run but after weeks in hiding he was caught and sent back to the North to be put on trial. He was sentenced to death for his part in the attempt to overthrow the Ascendency and was hanged at Downpatrick alongside other conspirators who had joined him in the enterprise.
His brave death was the subject of a famous ballad by Florence Wilson that ends with the death of Russell on the gallows:
For the man that they hanged at Downpatrick Jail
Was the Man from God-knows-where!