She spoke of her admiration for the three military services during a speech at Portsmouth naval base on Thursday.

Accompanied by the Duke of Edinburgh, she witnessed a number of military displays by the Royal Navy, the Army and the RAF.

The events in Hampshire were part of the latest leg in the Queen's Golden Jubilee tour and the military show of strength has cost more than �1m to stage.

Britain is grateful to you, whether here in Portsmouth, in bases across the United Kingdom or across the world

The Queen

She said: "I am only too well aware of the tremendous contribution the armed forces, including the volunteer reserves, have made to the standing and reputation of this country throughout the world during my reign.

"I owe a particular debt of gratitude to the many members of the armed forces who have given me and my family their personal support in so many different ways during the last 50 years."

The Queen paid a special tribute to the families of servicemen and women.

"I would like to take this opportunity to acknowledge the special strains that this service places on wives, husbands and families.

Difficult situations

"Service overseas, particularly in response to unexpected crises in distant parts of the world, inevitably disrupts family life and I want to pay tribute to all service families for their support and their toleration of frequent separation."

The public saw the success of Britain's armed forces in keeping the peace in difficult situations and their effective intervention when national interests were threatened.

The Queen said: "But I know that these contributions are only made possible by the continuing and very thorough process of training of individuals and units.

Welfare support

"The high standards at times of considerable stress are the product of an efficient command structure, close integration of the three services, good leadership and intensive practice."

She also paid tribute to the work of welfare and support organisations, such as the chaplains, medical services and members of the Women's Royal Voluntary Service and Forces' Help.

The Queen concluded: "Britain is grateful to you, whether here in Portsmouth, in bases across the United Kingdom or across the world."