Exhibit 99.1

ALLEGHANY CORPORATION

1411 Broadway, 34^th Floor

New York, NY 10018

ALLEGHANY CORPORATION REPORTS 2016 THIRD QUARTER RESULTS

NEW YORK, NY, November 1, 2016 – Alleghany Corporation (NYSE-Y) announced today its financial results for the three and nine months ended September 30, 2016. Highlights are listed below.

Weston Hicks, President and chief executive officer of Alleghany, stated, “Our third quarter results were strong and represent solid underwriting performance from each of our (re)insurance businesses and a positive contribution from Alleghany Capital as all of its businesses delivered improved results. A rebound in equity markets also contributed to Alleghany’s 2.4% growth in book value in the quarter. Alleghany’s underwriting results produced a combined ratio of 91.0% in the third quarter and 92.0% for the year to date. The third quarter underwriting results reflect favorable prior year reserve development of $86.4 million, primarily at TransRe and RSUI, partially offset by catastrophe losses of $32.1 million. We remain pleased with the performance at TransRe and our insurance businesses both of which are successfully executing on their operating plans in challenging markets.”

“During the third quarter, A.M. Best confirmed the financial strength ratings of RSUI, CapSpecialty and PacificComp and upgraded TransRe to A+ (Superior). We believe this upgrade, combined with TransRe’s valuable brand, strong capital and its global market presence, position TransRe well in the current environment.”

“Growth in net premiums written of 22.1% in the third quarter included increases at TransRe, CapSpecialty and PacificComp and was primarily attributable to the large whole account quota share treaty written by TransRe in the fourth quarter of 2015. PacificComp and CapSpecialty again delivered improved operating performance in the current quarter.”

¹ Stockholders’ equity attributable to Alleghany stockholders divided by common stock outstanding.

² Net earnings attributable to Alleghany stockholders.

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The following table summarizes results for the three and nine months ended September 30, 2016 and 2015:

“Recently, Hurricane Matthew struck the Bahamas, impacted the east coast of Florida and made landfall in the Carolinas. TransRe and RSUI are in the process of analyzing claims data and other information to estimate their ultimate losses from this event; however, it is too early to determine a reliable loss estimate.”

Mr. Hicks continued, “Alleghany Capital’s investment in closely-held private businesses was $650.6 million as of September 30, 2016. Alleghany Capital’s businesses generated revenue growth and improved performance, particularly at Jazwares, Kentucky Trailer and IPS, in the quarter. Alleghany Capital generated $7.8 million of earnings before income taxes and $20.3 million of Adjusted EBITDA for the three months ended September 30, 2016. In the third quarter, Alleghany Capital’s manufacturing and services businesses, which include ownership in Kentucky Trailer, IPS, Bourn & Koch and Jazwares, generated $16.7 million of earnings before income taxes and $25.6 million of Adjusted EBITDA, growth of 146% and 237% respectively. Alleghany Capital’s oil and gas business, primarily SORC, remains in its planned development phase and significantly reduced its operating loss with a loss before income taxes of $6.9 million and Adjusted EBITDA loss of $3.4 million.”

SEGMENT RESULTS

The following table summarizes the segment results for the three and nine months ended September 30, 2016 and 2015:

Reinsurance Segment

The increase in TransRe’s net premiums written in the third quarter and first nine months of 2016 from the corresponding 2015 periods primarily reflects $199.4 million and $624.2 million, respectively, of premiums recorded in connection with a large whole account quota share treaty placed as of December 31, 2015.

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TransRe’s 2016 third quarter combined ratio was 92.3%, compared with 92.6% for the 2015 third quarter, and TransRe’s combined ratio for the first nine months of 2016 was 93.9%, compared with 89.9% for the first nine months of 2015. TransRe’s higher combined ratio for the first nine months of 2016 primarily reflects higher catastrophe losses and a higher combined ratio on the whole account quota share treaty, partially offset by more favorable prior year loss reserve development. TransRe’s catastrophe losses in the quarter relate primarily to typhoons and floods in China.

Insurance Segment

The increase in the insurance segment net premiums written in the third quarter and first nine months of 2016 from the corresponding 2015 periods reflects continued growth at PacificComp and CapSpecialty, partially offset by competition-driven property insurance premium declines at RSUI. For the third quarter and first nine months of 2016, PacificComp’s net premiums written increased by 32.0% and 43.0%, respectively. CapSpecialty’s net premiums written increased by 16.7% and 15.4%, respectively, and RSUI’s net premiums written decreased by 4.8% and 5.8%, respectively.

The insurance segment’s 2016 third quarter combined ratio was 86.8%, compared with 86.7% for the 2015 third quarter, and the insurance segment’s combined ratio for the first nine months of 2016 was 86.1%, compared with 87.6% for the first nine months of 2015. The lower combined ratio and higher underwriting profit for the first nine months of 2016 primarily reflect more favorable prior year loss reserve development and the impact of growing net premiums earned at PacificComp, partially offset by higher catastrophe losses at RSUI.

Alleghany Capital

The following table summarizes earnings (losses) before income taxes and Adjusted EBITDA for Alleghany Capital for the three and nine months ended September 30, 2016 and 2015:

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INVESTMENT PERFORMANCE

Alleghany reported net investment income for the third quarter and first nine months of 2016 of $120.6 million and $332.3 million, respectively, an increase of 2.0% and a decrease of 0.7% from the corresponding 2015 periods. The increase in net investment income in the third quarter of 2016 from the third quarter of 2015 primarily reflects higher interest income from funds withheld by cedants. The decrease in net investment income in the first nine months of 2016 from the first nine months of 2015 primarily reflects lower earnings from partnership investments and equity-method investments included in other invested assets, partially offset by higher interest income from funds withheld by cedants. Financial statement total return³ on investments was 1.1% in the 2016 third quarter, compared with (0.6%) for the 2015 third quarter. Year-to-date financial statement total return was 4.0%.

OTHER FINANCIAL INFORMATION

As of September 30, 2016, Alleghany had 15,434,629 shares of its common stock outstanding, compared with 15,544,077 shares of its common stock outstanding as of December 31, 2015. As of September 30, 2016, Alleghany had $391.8 million remaining under its share repurchase authorization. During the third quarter of 2016, Alleghany repurchased 4,621 shares at an average price of $517.40 per share. During the first nine month of 2016, Alleghany repurchased 117,721 shares at an average price of $472.97 per share.

Additional Information

Concurrent with the issuance of today’s earnings press release, Alleghany has posted a financial supplement to its website, www.alleghany.com, containing additional schedules that provide further detail pertaining to Alleghany’s financial results.

Additional information regarding Alleghany’s 2016 third quarter and first nine months financial results, including management’s discussion and analysis of Alleghany’s financial condition and results of operations, is contained in Alleghany’s Quarterly Report on Form 10-Q for the period ended September 30, 2016 (the “Form 10-Q”), to be filed with the U.S. Securities and Exchange Commission (the “SEC”) on or about the date hereof. The Form 10-Q and the financial supplement will be available on Alleghany’s website at www.alleghany.com. The Form 10-Q will also be available on the SEC’s website at www.sec.gov. Readers are urged to review the Form 10-Q for a more complete discussion of Alleghany’s financial performance.

About Alleghany Corporation

Alleghany Corporation (NYSE-Y) creates value through owning and managing operating subsidiaries and investments, anchored by a core position in property and casualty reinsurance and insurance. Alleghany’s property and casualty subsidiaries include: Transatlantic Holdings, Inc. (referred to herein as “TransRe”), a leading global reinsurer; RSUI Group, Inc. (referred to herein as “RSUI”), a national underwriter of property and liability specialty insurance coverages; CapSpecialty, Inc. (referred to herein as “CapSpecialty”), an underwriter of commercial property, casualty and surety insurance coverages; and Pacific Compensation Corporation (referred to herein as “PacificComp”), an underwriter of workers’ compensation insurance, primarily in California. Alleghany’s subsidiary Alleghany Capital Corporation (referred to herein as “Alleghany Capital”) engages in and oversees strategic investments and acquisitions. Alleghany Capital’s investments include: (i) Bourn & Koch, Inc., a manufacturer and remanufacturer of precision machine tools as well as a supplier of replacement parts and related services; (ii) IPS-Integrated Project Services, LLC, a technical service provider focused on the global pharmaceutical and biotechnology industries; (iii) Jazwares, LLC, a licensed toy and consumer electronics company; (iv) R.C. Tway Company, LLC (dba Kentucky Trailer), a manufacturer of custom trailers and truck bodies for the moving and storage industry and other markets; and (v) Stranded Oil Resources Corporation, an

³ As calculated in Alleghany’s financial supplement.

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exploration and production company focused on enhanced oil recovery. For additional information about Alleghany Capital Corporation, please visit www.alleghanycc.com.

Non-GAAP Financial Measures

Throughout this press release, Alleghany’s results of operations have been presented in the way that Alleghany believes will be the most meaningful and useful to investors, analysts, rating agencies and others who use financial information in evaluating the performance of Alleghany. This presentation includes the use of underwriting profit, operating earnings per diluted share and Adjusted EBITDA, which are “non-GAAP financial measures.” The presentation of these financial measures is not intended to be considered in isolation or as a substitute for, or superior to, financial information prepared and presented in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”). Also note that these measures may be different from non-GAAP financial measures used by other companies, limiting their usefulness for comparison purposes. A discussion of our calculation and use of these financial measures is provided below.

Underwriting profit represents net premiums earned less net loss and loss adjustment expenses and commissions, brokerage and other underwriting expenses, all as determined in accordance with U.S. GAAP, and does not include net investment income, net realized capital gains, other than temporary impairment losses, other income, other operating expenses, corporate administration, amortization of intangible assets and interest expense. Alleghany consistently uses underwriting profit as a supplement to earnings before income taxes, the most comparable U.S. GAAP financial measure, to evaluate the performance of its segments and believes that underwriting profit provides useful additional information to investors because it highlights net earnings attributable to a segment’s underwriting performance. Earnings before income taxes may show a profit despite an underlying underwriting loss; and when underwriting losses persist over extended periods, a reinsurance or an insurance company’s ability to continue as an ongoing concern may be at risk.

A reconciliation of underwriting profit to earnings before income taxes is presented below.

Operating earnings per diluted share represents earnings per diluted share excluding (on an after-tax basis) net realized capital gains and other than temporary impairment losses, all as determined in accordance with U.S. GAAP. Alleghany uses operating earnings per diluted share as a supplement to diluted earnings per share, the most comparable U.S. GAAP financial measure, to provide useful additional information to investors by highlighting earnings per diluted share attributable to its performance exclusive of realized capital gains or losses and

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impairments. A reconciliation of operating earnings per diluted share to diluted earnings per share is presented below.

Adjusted EBITDA is a non-GAAP financial measure for Alleghany’s non-insurance operating subsidiaries and investments held by Alleghany Capital. Adjusted EBITDA represents other revenue less certain other expenses, and does not include depreciation expense (a component of other operating expenses), amortization of intangible assets, interest expense, net realized capital gains, OTTI losses, and income taxes. Because Adjusted EBITDA excludes interest, income taxes, depreciation and amortization, it provides an indication of economic performance that is not affected by levels of debt, interest rates, effective tax rates or levels of depreciation and amortization resulting from purchase accounting. Alleghany uses Adjusted EBITDA as a supplement to earnings before income taxes, the most comparable U.S. GAAP financial measure, to evaluate the performance of certain of our non-insurance operating subsidiaries and investments. A reconciliation of Adjusted EBITDA to earnings before income taxes is presented above in “Segment Results-Alleghany Capital.”

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Forward-looking Statements

This release contains disclosures which may be deemed to be “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by the use of words such as “may,” “will,” “expect,” “project,” “estimate,” “anticipate,” “plan,” “believe,” “potential,” “should” or the negative versions of those words or other comparable words. Forward-looking statements do not relate solely to historical or current facts rather are based on management’s expectations as well as certain assumptions and estimates made by, and information available to, management at the time. These statements are not guarantees of future performance. These forward-looking statements are based upon Alleghany’s current expectations and are subject to a number of uncertainties and risks that could significantly affect current plans, anticipated actions and Alleghany’s future financial condition and results. Factors that could cause these forward-looking statements to differ, possibly materially, from that currently contemplated include:

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Additional risks and uncertainties include general economic and political conditions, including the effects of a prolonged U.S. or global economic downturn or recession; changes in costs; variations in political, economic or other factors; risks relating to conducting operations in a competitive environment; effects of acquisition and disposition activities, inflation rates, or recessionary or expansive trends; changes in interest rates; extended labor disruptions, civil unrest, or other external factors over which we have no control; changes in our plans, strategies, objectives, expectations, or intentions, which may happen at any time at our discretion; and other factors discussed in Alleghany’s most recent Annual Report on Form 10-K and subsequent filings with the SEC. All forward-looking statements speak only as of the date they are made and are based on information available at that time. Alleghany does not undertake any obligation to update or revise any forward-looking statements to reflect subsequent circumstances or events.

For more information, please contact:

Kerry Jacobs

Alleghany Corporation

212-508-8141

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Item 1. Financial Statements

ALLEGHANY CORPORATION AND SUBSIDIARIES

Consolidated Balance Sheets

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ALLEGHANY CORPORATION AND SUBSIDIARIES

Consolidated Statements of Earnings and Comprehensive Income (Loss)

(unaudited)

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ALLEGHANY CORPORATION AND SUBSIDIARIES

Consolidated Statements of Earnings and Comprehensive Income

(unaudited)

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