National Trust workers have voted to accept a 4.5% pay offer, described by their union as a "ground-breaking" deal.
Prospect said it had also agreed to hold further talks about creating a comprehensive "well-being strategy" for the Trust's staff.
Prospect officer Matt Sperring said: "The National Trust's pay offer is recognition of the valuable contribution its staff make which has led to an uplift in its financial performance over the last 12 months."
Prospect National Trust branch president Paul Stewart added: "Strong membership figures have been pivotal in creating a partnership of equals between the National Trust and Prospect."
Tina Lewis, National Trust director of people and legal services, said: "It's important that we recognise the hard work of our staff and reward high performance.
"A bigger proportion of this than ever before will be invested in our lower paid staff and we continue to pay the National Living Wage as a minimum.
"To ensure we retain, recruit and reward great employees, we need to pay our people a competitive salary which reflects the current market rates."