Barbara Castle, born in October 6th, 1910, was one of the most successful female Labour politicians of the 20th Century. She served in the Department of Transport, overseeing the introduction of permanent speed limits, alcohol breath tests and compulsory seat belts. In the Employment Department she brought in he Equal Pay Act, and she also served in Overseas Development and Health and Social Security.

However, it is probably something she didn’t do that will be recorded in the history books. In an attempt to bring the trade unions within the law, she proposed to limit their powers in her 1969 white paper, “In Place of Strife.” Union bosses were bringing the country to its knees by exercising industrial power with arrogant, bullying tactics that were beyond the rule of law. They rebelled against her plans, and found a ready friend in James Callaghan, who fought against her proposals in Cabinet. The Cabinet was split, resignations were threatened, and the Labour paper, Tribune, campaigned publicly against her for attacking workers rather than bosses. She was forced to climb down as the bill was diluted to ineffectiveness. The unions had won.

She began a hate-hate relationship with James Callaghan, who dismissed her from an otherwise little-changed Cabinet when he became PM. His excuse that he wanted to lower its average age looked thin, since he was himself 4 years older than Harold Wilson, the PM he replaced. Castle became an MEP, and in 1990, a life peer.

She had failed to tame the unions, as did Edward Heath when he unexpectedly won the 1970 general election and introduced his “Industrial Relations Act.” The unions fought back bitterly with a series of strikes that brought power cuts and a three-day working week. Heath called an election in 1974, asking “Who runs the country?” The electorate replied, “Not you,” and booted him out. The unions had won again, and Heath was demoted to sulk for years on the back benches.

Margaret Thatcher did bring the unions to heel, where both Castle and Heath had failed. There were three elements to her success. Firstly, she didn’t initially confiscate union power, but redistributed it from the union leaders to their members. Thus there were now secret postal ballots for members to elect their leaders, in place of a show of hands at the workplace under the eye of shop stewards. Workers voting at home began to elect more moderate leaders. There were postal ballots, too, as workers won the right to be consulted before strikes could be called. This deprived their leaders of the ability to call instant walk-outs.

The second element of the Thatcher government’s approach was that it was piecemeal. Instead of one big act that would provoke total opposition, there were a series of measures, each fairly small, but cumulatively they gradually brought the unions under control. It was a salami slicer approach.

Her third element was privatization. Putting the big state industries into private hands changed the attitude of their workforce. Strike action now could threaten their own jobs, and their company’s long term survival. Britain went from having the highest number of days in Europe lost through strike action, to having the lowest. Such industrial unrest as remained was now mainly confined to industries and services that remained in the public sector.

Thatcher succeeded where Castle and Heath had failed, by adopting a gradualist, Fabian, approach. Jeremy Corbyn’s policy of reintroducing those lost union powers shows how effective their abolition was in curbing extremist left wing militancy.

Barbara Castle was 87 when she sat in the front VIP row in Cambridge’s Senate House when I graduated with my Master’s degree in 1997. I don’t think she knew she was watching the President of the Adam Smith Institute. Had she done so, she might well have walked out.