Productive Estate System: the main sleeve. This represents the manor as an integrated economic engine: land, buildings, productive territory, embedded labor, agricultural output and enforcement capacity. In modern terms it can be proxied only imperfectly with direct rental property, rural or mixed-use real estate, listed real-estate companies, SOCIMIs, global REIT UCITS ETFs, farmland exposure or real-asset funds. A higher-fidelity version would combine property ownership with operating-business exposure, because the historical estate was not passive real estate.
Local Monopolies & Private Rights: proxy for mills, tolls, market rights, workshops, bridges, local concessions and legally protected income streams. Today this maps to small private businesses with local dominance, infrastructure concessions, niche service businesses with pricing power, family businesses, private equity or listed infrastructure and alternatives where private access is not available.
Precious Metals: proxy for coin, plate, jewels and portable treasure. Modern implementation can use physical gold, allocated gold products or gold ETCs available to Spanish investors.
Strategic Liquidity: small reserve for taxes, repairs, obligations, emergencies and opportunistic purchases. Use insured bank deposits, Letras del Tesoro, EUR money-market funds or very short-term EUR cash ETFs.
Account notes: This model is intentionally concentrated, illiquid and real-asset heavy. Direct property fits the spirit of the portfolio but can dominate the whole balance sheet too easily. Listed real estate, cash-like instruments, gold and infrastructure proxies make the model more investable, but also less historically faithful. The Productive Estate System and Local Monopolies sleeves are the hardest to implement passively because they historically depended on control, local dominance and operating authority rather than simple ownership of securities.
Costs: Keep liquid sleeves cheap and transparent. Avoid high-fee private real-estate, private-equity, infrastructure or commodity products unless the investor clearly understands lockups, leverage, valuation methods and exit constraints. The medieval model already carries structural illiquidity and concentration risk; do not add unnecessary product complexity.
Rebalancing: Use structural or event-driven rebalancing rather than pretending this can be precisely rebalanced every year. Direct property and private business exposure cannot be adjusted cleanly. Use new contributions, dividends, rents, refinancing proceeds or liquidity events to move the portfolio gradually back toward target weights. The Strategic Liquidity sleeve should be protected from being absorbed by property expenses.
Tax: Spanish taxation can differ significantly between rental income, SOCIMIs, ETFs, fondos de inversion, gold products, deposits, Letras del Tesoro and private-company ownership. Direct property also brings IBI, maintenance costs, transaction taxes and potential capital-gains taxation. Eligible Spanish mutual funds may allow tax-deferred transfers, while ETFs and ETCs generally do not receive the same treatment.
Product names are implementation examples for research. Availability, taxation, share classes and suitability should be checked with the investor's broker and tax situation.