Royal Caledonian Ball Grosvenor House Hotel, 86-90 Park Lane, London W1A 3AA Details from Mrs Roger Tym, The Old Manse, High Street, Stockbridge, Hampshire SO20 6LE (telephone 01264 810363). Held on the first Thursday in May and often attended by Princess Margaret. In aid of the Royal Caledonian Schools and other Scottish charities. Horse Racing Chester, Cheshire Details from The Racecourse, Chester, Cheshire CH1 2LY (telephone 01244 323170). York, Yorkshire Details from York Racecourse, York, Yorkshire YO2 1EX (telephone 01904 620911). Royal Windsor Horse Show Windsor, Berkshire Details from The Secretary, Royal Windsor Horse Show, Royal Mews, Windsor Castle, Windsor, Berkshire SL4 1NG (telephone 01753 860663). Held over 5 days at Home Park, Windsor, by kind permission of the Queen. Polo May is when the polo season starts and runs through until September. Details from these polo clubs: Ascot Park Westcroft Park Farm, Windlesham Road, Chobham, Surrey GU24 8SN (telephone 01276 858545). Beaufort Down Farm, Westonbirt, Tetbury, Gloucestershire GL8 8QW (telephone 01666 880214). Cambridge and Newmarket Lower Farm, Dullingham, Newmarket, Cambridgeshire (telephone 01223 847379). Checkendon Park Lovegroves Lane, Checkendon, Reading, Berkshire. (telephone 01491 682266). Cheshire The Oulton Grounds, Little Budworth, Cheshire (telephone 01836 600317). Cirencester Park The Old Kennels, Cirencester Park, Cirencester, Gloucestershire GL7 1UB (telephone 01285 653225). Cowdray Park The Estate Office, Cowdray Park, Midhurst, West Sussex GU29 0AQ (telephone 01730 813257). Epsom Horton Country Park, Horton Lane, Epsom, Surrey KT19 8PL (telephone 01372 362953). Guards Smith's Lawn, Windsor Great Park, Englefield Green, Egham, Surrey TW20 0HP (telephone 01784 434212). Ham The Clubhouse, Ham House Grounds, Petersham Road, Richmond, Surrey TW10 5HL (telephone 0181-940 2020). Kirtlington Park Kirtlington Park, Kirtlington, Oxfordshire (telephone 01869 350521). Knepp Castle Knepp Castle, West Grinstead, near Horsham, West Sussex RH13 8LJ (telephone 01403 741007). Royal County of Berkshire North Street, Winkfield, Windsor, Berkshire SL4 4TH (telephone 01344 890060). Rutland Rutland Showground, Oakham, Leicestershire (telephone 01664 79235). Silver Leys Carver Barracks, Saffron Walden, Essex CM6 3QF (telephone 01371 8303255). Stoneleigh Park Gatehouse, Stoneleigh Abbey, Kenilworth, Warwickshire CV8 2IF (telephone 01926 851989). Tidworth Tidworth Combined Services Polo Club, Arcot Road, Tedworth Park, Tidworth, Wiltshire SP9 7AH (telephone 01980 846705). Toulston Toulston Park, near Tadcaster, Yorkshire HX4 0BG (telephone 01422 372529). Badminton Horse Trials Badminton, Avon Details from Badminton Horse Trials Office, Badminton, Avon GL9 1DF (telephone 01454 218375). Held in early May. Chelsea Flower Show Chelsea, London Details from the Royal Horticultural Society, Vincent Square, London SW1P 2PE (telephone 0171 630 7422). Marquees house the main exhibitors, as well as specially designed gardens many of which follow a theme. Monday is royal private viewing day with a gala charity preview in the evening. Tuesday and Wednesday are RHS members' days, and Thursday and Friday are for the public. British Antique Dealers' Association Fair Chelsea, London Details from BADA/Reed Exhibitions Ltd, Oriel House, 26 The Quadrant, Richmond, Surrey TW9 1DL (telephone 0181 948 9802). Held during the first week of May. Rugby Cup Final Twickenham, London Details from the Rugby Football Union, Twickenham, Middlesex TW1 1DZ (telephone 0181 892 8161). International Golf Open St Mellion, Cornwall Details from Gallaher Limited, Members Hill, Brooklands Road, Weybridge, Surrey KT13 0QU (telephone 01932 859777). Cavalry Parade Hyde Park, London Details from local press. Combined Cavalry 'Old Comrades' Parade and Memorial Service at the Cavalry Memorial in Hyde Park, held on the first or second Sunday in May. Football Association Cup Final Wembley, London Details from Football Association, 16 Lancaster Gate, London W2 3LW (telephone 0171 262 4542). Floral Luncheon Savoy Hotel, London Details from Forces Help Society and Lord Roberts Workshops, 122 Brompton Road, London SW3 1JE (telephone 0171 589 3243). In aid of the Forces Help Society and the Lord Roberts Workshops, held on the first Thursday in May. Royal Society of Portrait Painters Annual Exhibition Mall Galleries, London Details from Royal Society of Portrait Painters, 17 Carlton House Terrace, London SW1Y 5BD (telephone 0171-930 6844). Includes a mixture of pictures by established painters and members of the public. ISS Spring Fair Kensington Town Hall, London Details from ISS UK, Cranmer House, 39 Brixton Road, London SW9 6DD (telephone 0171 735 8941). Brings together the diplomatic corps of London in aid of the International Social Service of the UK. Features stalls from over a hundred countries and many of the diplomatic wives based in London become sales assistants for the day. Each stall is piled high with unusual and attractive produce from each country. Jester Ball London Details from the Action on Addiction Office, 68 South Lamberth Road, London SW8 1RL (telephone 0171 793 1011). In aid of Action on Addition. Gulls' Egg City Luncheon London Details from The CRMF Appeals Office, 11 Elvaston Place, London SW7 5QG (telephone 0171 581 9225). In aid of the Cancer Relief Macmillan Fund. Gulls' eggs are the focal point of the menu. Glyndebourne Opera Festival Lewes, East Sussex Details from Glyndebourne Festival Opera, Glyndebourne, Lewes, East Sussex BN8 5UU (telephone 01273 812321). Held between May and August. May Balls and Commemorative Balls Oxford and Cambridge Given at and by individual Oxford and Cambridge colleges. At Oxford the balls are known as Commem Balls instead of May Balls, but are otherwise the same. Admission is by ticket but invitations are normally circulated to current undergraduates in January and February and any remaining tickets are then allocated to the public. For further information, contact the individual colleges. Other universities organise similar festivities. Major-General's Review, Trooping the Colour Whitehall, London Details from Senior Public Relations Officer, London District, Chelsea Barracks, London SW1H 8RF (telephone 0171 930 4466 ext 2396/2357). First rehearsal. Held at the end of May. Bath International Music Festival Bath, Avon Details from Bath Festivals Trust, Linley House, 1 Pierrepont, Bath, Avon BA1 1JY (telephone 01225 462231). Held between the end of May and beginning of June. Hickstead Nations Cup Show Jumping West Sussex Details from Booking Office, All England Show Jumping Course, Hickstead, West Sussex RH17 5NU (telephone 01273 834315). Remember: The Proms Book tickets well in advance. Details from Royal Albert Hall, Kensington Gore, London SW7 2AP (telephone 0171-589 8212). Royal International Agricultural Society Show Apply for tickets before mid June to take advantage of a 33% discount. Details from Royal Agricultural Society of England, National Agricultural Centre, Stoneleigh, Warwickshire CV8 2LZ (telephone 01203 696969).