What have been the most significant developments in HR over the last 50 years?

The Employment Rights Act 1996

Indeed. Significantly amended during the 90s by Blair govts[?]

(a) Equal opps. legislation - starting with Equal Pay / Disability Discrimination Acts / Sex Discrimination Act........and of course current Equality Act etc
(b) Mandatory adoption as a member state of miscellaneous EU employment rights directives etc

Decline of trade unionism (other than in the public sector)
Being in HR not Personnel Departments?

and before Personnel - Welfare and Wages!

1970s a belief that legislation would change things - sex discrimination act, race relations act , Equal pay act etc. All promise but disappointing delivery. Strong trade union power and predominance of ER specialists in Personnel departments - rest largely admin and functional training 

1980s Thatcherism, recession, mass unemployment. Government targeting TU power. Start of decline in final salary pensions and job for life mentality. Movement to more a transactional employer/employee relationship. Rise of management training (and 90s) activity based. 

1990s Rise of HR Management and moving away from welfare role. Continued decline of Trade Unions. race away from final salary pensions in the private sector. Introductions of mainstream HR systems to allow greater data analysis and insight. Individualism rather than collectivism. Start of movement upwards (I think) in right to bring an ET case/unfair dismissal protection. Assessment centre selection and psychometric in vogue 

2000s Main influence of European legislation - WTR, Minimum Wage, Age Discrimination etc Blairism etc. Second round of belief that legislation makes a real difference but with more success this time. Mass migration and opening up of labour markets, skills shortages. Huge increase in graduate workforce leading to graduates (with debt) taking non graduate jobs. removal of compulsory retirement age and increase in state retirement ages radically changing long term nature of work

2010s migration , technology, Europe etc... Move to blended and more flexible learning solutions away from traditional classroom. Equality Act trying to bring everything together. Codifying rather than extending rights. HR as an enabler and architect rather than an owner.

It was 'Labour Officers' etc in the 'Labour Department' when I first started - ie the necessary specialist front line / interface between the employer and (their almost 100% trade unionised) workpeople. There was a 'Personnel Manager' who ran the Labour Dept. but only from a comfortable and exalted location well behind the front line, out of range of all the grimy hands and boots and raised voices.

Re Personnel  HR. Was that a turn of the century thing? 

I recall my father working in a council Personnel Dept back in the 70s. I remember a huge 'walk-in' safe for some of the files. He was an 'office manager / admin' man though. 

Epic, Keith

I don't think the rise of the desktop computer or the influence of the Internet can be overlooked. Together, they've transformed recruitment and created new job categories and even whole industries from nothing.

In the 1990s we saw the rise of email as the new tool of management.

In the 2000s we saw the creation of the website and the first online recruiment sites, along with the increasing ubiquity of digital tools for managing people and payroll.

In the 2010s social media became the new technological battlefield, creating as many problems as it did solutions.

In the 2020s, I expect automation and the intrusion of AI into routine workplace tasks to be the new technological disruptor for HR (as well as everything else).