From Gallifrey to Glenbogle Monk. Soldier. Time Lord. Now Tom Baker's arrived in Monarch of the Glen. And he's loving every minute. By Mark Smith

for 55 years; a voice that has been used in a 100 ads to sell cough

mixture and insurance. It is also the voice that ordered Daleks to retreat. And retreat they did, of course.

So, naturally, it is the voice I notice first as I am waiting to be introduced to him on the set of Monarch of the Glen, in the Highland village of Kingussie. It is bellowing good-humouredly at an assistant. ''I'm a stamp now,'' he booms as I climb into his trailer. He is holding up a strip of stamps which show him in Doctor Who, all woolly scarf and white-out grin. You and the Queen, I say. Quite

an achievement.

And it is. It may just be a stamp, but it is a measure of the cult status Baker has achieved over the past 30 years that he is now part of the British postal system. That may explain why the producers of the sixth series of Monarch turned to him when considering their casting. An icon joining a cult can't be bad for viewing figures.

Of course, Monarch is no ordinary cult. It is the kind of show that is knitted rather than produced; full of look-at-me scenery and characters and storylines that emit a comforting warmth. Baker has glided into the series like a mountain on the move and his performance as Donald

MacDonald, a septuagenarian mischief-maker, is a scream. The only problem is that he does have a tendency to tower, like the Wallace Monument, over every other performance. His co-star, Martin Compston, has been the first to admit that everyone else has suddenly had to raise their game.

Like the previous five, this series of Monarch is being filmed at the big house on the Ardverikie estate and in Kingussie. Not that you would know it in the village today. The only indication that a TV crew is here is a small yellow sign that reads M O T G and points to two unprepossessing caravans. Baker is sharing his with some of the minor cast members, but doesn't seem

to mind.

In a twist on his fictional existence, the inside of his caravan is smaller than the outside, which means Baker looks simply massive. He is 6ft 3in, and in his younger days, could have been a bouncer. For all I know, he was. After all, he worked in a whole lot of jobs before starting work on Gallifrey. The brown curls he had in those days have gone grey and flat but, despite being 70, he seems youthful. In fact, there is something about him that means you could reverse 70 to 07 and it would still make sense.

Clearly, he is enjoying being in Monarch. Most of his scenes are with Compston. The young star is only 20 and wouldn't know a Tardis if it materialised in front of him, so he treats Baker just like anyone else. The older actor jokes that he is The Past and Compston is The Future. ''He's a very clever, intuitive actor,'' says Baker. ''And he's probably going to be a

movie star.''

Apart from the cast, the joy for Baker is playing a character that is, let's face it, a fictionalised version of himself. ''I suppose he's a bit like me: a self-deluded old fool.'' But there may be another reason Baker is enjoying himself. You see, what with his lovely BBC flat and the lovely BBC staff, he is living in a bit of an institution, and there's nothing Tom Baker likes more than an institution. In fact, his life is a series of them. First: a monastery. Second: the army. Third: drama school. The period as a monk may be the hardest to understand, but only if you don't know his background.

Baker was born in Liverpool in 1934 into a working-class community that still bought into the mantra ''Blessed are the poor''. In fact, he remembers his mother, Mary, turning to her sister and saying, with all the blindness of faith: ''Thank God we're poor.'' ''The more poor people are, the more likely they are to dream,'' says Baker, ''because dreams are available to everyone.''

So he went to become a monk

at 15, led by a desire for self-abnegation. For six years, he was not permitted to look at himself or another person and so, in due course, that was all he wanted to do. Eventually, it was too much, he left, and he was pinged back into life with a force that is carrying him still. Looking back, Baker can only see life in that monastery as twisted and sick. ''I see it as absolutely f*****g preposterous. I absolutely chortle with derisive laughter at it and chuck another pint down my neck. The whole vile thing about that fundamentalist Christianity is that we are

unworthy. If you keep telling a child, 'You are nothing', the child

cannot possibly grow up with

self-esteem.''

Life after the monastery could not have been more different. Success had still to turn up, apologising profusely for being so

late, and until then, there were women.

''My faith vanished swiftly when I bumped into a couple of girls in Germany,'' he says with a Richter-scale laugh. ''It was incredible. God must have been livid. When you're young - me especially with all those years of chastity - I had this amazing, vital libido. So when I had nothing but a toothbrush and a libido, and I'd ditched my guardian angel and stopped being inhibited by him, it

was wonderful.'' He is an atheist now, but isn't against religion. ''People are quite happy believing the wrong things. I wasn't unhappy believing all that s***. Now I'm not unhappy thinking about it because I can laugh at it.''

Freed from the monastic life, there was another institution which Baker was to experience: The Family. He has been married three times (once to his Doctor Who co-star Lalla Ward), but it is the first one which has perhaps left the deepest scars. Although the marriage produced two sons, Baker's relationship with his wife's family was difficult. His father-in-law, in particular, did not like Baker, yet when he was struck down by terminal illness it was Baker, as a former army

nurse, who was the only one who could care for him. ''He didn't really like me much, yet it was the person he didn't like much who was the only one who could comfort him because I had those skills. He was difficult, but when you are sick, no matter how clever you are, BANG, you are cut down by fate.''

He is still regularly in touch with his son, Piers, a horticulturist; his other son, Daniel not so much. ''I'm in touch in the sense that he knows where I am and I know where he is, but I don't see him. But the other fella has been to see me in France. There were big gaps in my life because of being divorced and away and travelling, but when I do see them they are amusing and I like them. I like them a lot.''

Suddenly Baker's mobile goes off and he looks at it suspiciously. This is the man who could understand the workings of a Type 40 Tardis, yet, delightfully, he is not comfortable with technology. He certainly can't retrieve his messages. ''My last shots are on Thursday,'' he fog-horns at the person on the other end. ''Yes, Thursday. Gooodbyeeee.''

Then we are back into the stories. I realise some of them are tall-ish, but they are marvellous nonetheless, so marvellous, in

fact, that I suspect he's had a scriptwriter working on them before my arrival, just to make

sure they're perfect. What's noticeable is that they are always aimed back at himself, which is typical of his self-deprecation. In fact, he claims to have had only three successes in his life.

The biggest one was Doctor Who and Baker thinks he knows why. ''It's that universal thing, isn't it? This amazement. Suddenly a box appears, and a door opens and a fellow comes out and says, 'Hello'. And then he can take you somewhere.'' The only problem was that as his stint from 1974-1981 rolled on, it became harder to see the joins between the Liverpudlian and the Gallifreyan. ''I began after a while to become so proprietorial about it so I thought I'd better give someone else a go.''

As for the new series starring Christopher Eccleston, Baker is cool. ''They are just so short of ideas, so they bring back formulas that were once successful. But the really delicate thing is how are they going to make it work?''

Baker's love for Doctor Who seems genuine and ultimately, it appears he liked it so much because the Doctor wondered at the universe and mysterious planets orbiting distant suns. It is an attitude Baker has tried to use himself. He wants to see as much as he can, experience as much as he can, live as much as he can. ''If your whole life is Newtonmore or Kingussie, you know, nice place to be, but if you think that's the world, you're wrong.''

Not that Baker hates the Highlands. Quite the opposite (well, apart from the midges). It's just that he's been here six months now and, with the greatest respect, it's time to go. A cup of milky tea at Pam's Coffee Shop in Kingussie can't compete with a beer in Soho. Or a glass of wine in France where he lives with his wife, Sue.

Baker loves his French home dearly, even if he is slightly mystified about how he ended up there. He has a beautiful house, a garden and a courtyard. No friends, though, because Tom Baker doesn't do friends. ''I don't have much of a capacity for friendship. I have a great capacity for the moment, but one of the burdens of friendship is it's more than a moment. You have to work at it.''

Don't think for a minute, though, that Baker is melancholic because he's not. He has thought deeply about his life, yes, because it has been one of extremes. Religion. Fame. Illness. Separation. Poverty. Wealth. But his conclusion seems to be a happy one: Enjoy. The BBC has already asked him back for the next series of Monarch, but that is the future. Something for time-travellers. A concept, that's all, and Tom Baker is far too busy with the present to worry about that.

The new series of Monarch of the Glen starts on Sunday on BBC1 at 8pm. Tom Baker appears in episode two on October 3.