aid: alleghany
name: Alleghany Corporation
description: >-
  Alleghany Corporation is a holding company engaged in property and casualty
  reinsurance and insurance through its subsidiaries, with additional
  investments in non-financial businesses held via Alleghany Capital. Founded
  in 1929 by railroad entrepreneurs Oris and Mantis Van Sweringen, the company
  transitioned over decades from rail holdings into specialty insurance and
  reinsurance, and is headquartered at One Rockefeller Plaza in New York City.
  Its principal insurance subsidiaries are Transatlantic Reinsurance Company
  (TransRe), a global reinsurer founded in 1977 with roughly 600 employees
  across 23 offices and more than $40 billion in claims paid to date; RSUI
  Group, a wholesale excess and surplus (E&S) underwriter spanning Property,
  Casualty, Professional Liability, Management Liability, and Binding
  Authority lines; and CapSpecialty, a specialty casualty and surety
  underwriter. Alleghany Capital holds non-insurance operating companies
  including toy and collectibles maker Jazwares (Squishmallows, Pokémon,
  Roblox, Fortnite licensed lines). On March 21, 2022, Berkshire Hathaway
  announced an $11.6 billion all-cash acquisition of Alleghany at $848.02 per
  share, which closed in October 2022. Alleghany now operates as a
  wholly-owned subsidiary of Berkshire Hathaway, contributing approximately
  $8.8 billion in 2025 gross premiums written and roughly $14 billion in
  insurance float to the parent. As a holding company whose operating units
  distribute exclusively through reinsurance intermediaries, wholesale
  brokers, and independent agents, Alleghany and its subsidiaries do not
  publish a developer portal, OpenAPI specifications, SDKs, or any other
  machine-readable API artifacts; the only digital surfaces exposed publicly
  are gated broker and agent login portals.
type: Index
position: Consumer
access: 3rd-Party
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
url: >-
  https://raw.githubusercontent.com/api-evangelist/alleghany/refs/heads/main/apis.yml
tags:
  - Insurance
  - Reinsurance
  - Property And Casualty
  - Specialty Insurance
  - Excess And Surplus
  - Surety
  - Financial Services
  - Holding Company
  - Berkshire Hathaway Subsidiary
  - Toys And Collectibles
  - Fortune 500
created: '2026-04-19'
modified: '2026-05-23'
specificationVersion: '0.19'
apis: []
common:
  - type: DomainSecurity
    url: security/alleghany-domain-security.yml
  - type: Website
    url: https://www.alleghany.com
  - type: ContactUs
    url: https://www.alleghany.com/contact-us/
  - type: ParentCompany
    url: https://www.berkshirehathaway.com
  - type: Subsidiary
    name: TransRe (Transatlantic Reinsurance Company)
    url: https://www.transre.com
  - type: Subsidiary
    name: RSUI Group
    url: https://www.rsui.com
  - type: Subsidiary
    name: CapSpecialty
    url: https://www.capspecialty.com
  - type: Subsidiary
    name: Jazwares
    url: https://www.jazwares.com
  - type: AgentLogin
    name: RSUI Broker Portal
    url: https://www.rsui.com/brokers/
  - type: PressRelease
    name: Berkshire Hathaway Acquires Alleghany (Mar 21, 2022)
    url: https://www.berkshirehathaway.com/news/MAR2122.pdf
  - type: GitHubOrganization
    name: TransRe (empty - 0 public repos)
    url: https://github.com/TransRe
maintainers:
  - FN: Kin Lane
    email: info@apievangelist.com