SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* FAIRFAX FINANCIAL HOLDINGS LTD/ CAN (Last) (First) (Middle) 95 WELLINGTON STREET WEST, SUITE 800 (Street) TORONTO, ONTARIO M5J 2N7 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol ZENITH NATIONAL INSURANCE CORP [ ZNT ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 09/29/2005
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock, $1.00 Par Value	09/29/2005		S		74,300	D	$63.7	0	I	Held by Odyssey America Reinsurance Corporation
Common Stock, $1.00 Par Value	09/29/2005		S		83,224	D	$63.7	0	I	Held by Clearwater Insurance Company

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
5.75% Convertible Senior notes due 2023 (the "Senior Notes")	(1)	09/29/2005		S			$30,000,000(2)	(3)	03/30/2023	Common Stock(4)	1,200,000	$76,440,000	0	I	Held by Odyssey America Reinsurance Corporation

1. Name and Address of Reporting Person* FAIRFAX FINANCIAL HOLDINGS LTD/ CAN (Last) (First) (Middle) 95 WELLINGTON STREET WEST, SUITE 800 (Street) TORONTO, ONTARIO M5J 2N7 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* WATSA V PREM ET AL (Last) (First) (Middle) 95 WELLINGTON STREET WEST, SUITE 800 (Street) TORONTO, ONTARIO M5J 2N7 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* CLEARWATER INSURANCE CO (Last) (First) (Middle) 300 FIRST STAMFORD PLACE (Street) STAMFORD CT 06902 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* ODYSSEY AMERICA REINSURANCE CORP (Last) (First) (Middle) 300 FIRST STAMFORD PLACE (Street) STAMFORD CT 06902 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. The Senior Notes are convertible into the number of shares of Common Stock of ZNT equal to the quotient obtained by dividing the principal amount of such Senior Notes by $25.00, subject to adjustment under certain circumstances.

2. $30,000,000 aggregate principal amount of Senior Notes.

3. The Senior Notes are currently convertible into 1,200,000 shares of Common Stock of ZNT.

4. Common Stock, $1.00 par value.

	/s/ Paul Rivett	10/03/2005
	/s/ V. Prem Watsa	10/03/2005
	/s/ Robert Giammarco	10/03/2005
	/s/ Robert Giammarco	10/03/2005
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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