The results reflect our ongoing initiatives to grow our core revenue and selected product development to create a business that is more sustainable for the future, complemented by value enhancing acquisitions.
We have delivered a strong financial performance during the year benefitting from both organic growth and the acquisition of Helmets & Armor. Revenue and adjusted operating profit grew by 30.8% and 33.6% respectively; an increase of 0.1% and 8.9% on an organic continuing operations basis.
Orders received of £160.8m (2019: £129.8m) supported an increase in revenue to £168.0m (2019: £128.4m) reflecting the benefit of the inclusion of 9 months of performance from Helmets & Armor. On an organic constant currency basis, revenue grew by 0.1% with Military revenue reducing by 3.6% given the strong comparator in 2019, offset by First Responder which grew strongly by 7.7% notwithstanding our exit from the Fire SCBA market.
Our adjusted EBITDA margin of 22.9% (2019: 22.1%), increased by 1.4% on an organic constant currency basis excluding the impact of Helmets & Armor. This primarily reflected the benefits of the commercial pricing of the new M50 and M53A1 DOD contracts and the strong performance from higher margin First Responder revenues. Adjusted EBITDA was £38.4m (2019: £28.4m); eliminating the effect of the Helmets & Armor acquisition and currency movements organic adjusted EBITDA grew by 6.8%.